03 1 M
THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
PRESENTED BY
PROF. CHARLES A. KOFOID AND
MRS. PRUDENCE W. KOFOID
>f
L\U
XXVIII. Description o/'Parkeria <m(Z Loftusia, two gigantic types of Arenaceous Fora-
minifera. By WILLIAM B.j CARPEXTEE, M.U., V.P.E.S., and HENRY B. BEADY,
F.L.S.
Received March 18, Eead April 22, 1869.
Introduction.
Ix the " Concluding Kemarks " appended to Part II. of my " Researches on the Fora-
minifera " (Philosophical Transactions for 1856, p. 565), I pointed out that the System
of Classification of that group which had been erected by M. D'ORBIGNY on the exclu-
sive basis of 2>lan of growth, was inconsistent with the facts disclosed by a careful study
of the organization of the five typical Genera described in my first and second Memoirs :
since it had the effect of bringing together Genera whose strongly marked physiological
differences required that they should be separated by the widest possible interval; whilst
it ranked under different Orders generic types which exhibit the closest physiological
relationship. And I then laid it down as a fundamental principle, " that physiological
conformity in the condition of each individual segment, as indicated by the structure of
its shelly investment, is a character of primary importance; whilst the plan of groiuth,
that is, the mode of increase in the number of chambers, is a character of subordinate
importance." And in the " Concluding Summary " appended to Part IV. (Philosophical
Transactions, 1860, p. 569), I further expanded this doctrine, by showing that all the
types which I had described might be ranged in two parallel Series : one of them cha-
racterized by that peculiar texture of the Shell which had been appropriately designated
PorceUanous by Professor W. C. WILLIAMSON*; whilst the shell-substance of the other
has the texture which had been described by the same excellent observer, with equal
appropriateness, as Hyaline or Vitreous. A third type of Shell-structure had been noticed
by Professor W. C. WILLIAMSON (loc. cit.) under the designation Arenaceous ; the shell
being mainly formed, not by a calcareous exudation from the sarcode-body of the animal,
but by the aggregation of particles of sand obtained from without, the cement by
which these are attached together being all that the animal supplies. These differences
in the character of the Shell were regarded by Professor W. as indicative of " physiolo-
gical differences in the living sarcode, or secreting animal substance, that have at least
<t specific value :" but while expressing (p. :;ix) a strong opinion as to the unphiloso-
phical nature of M. D'OEBIGXY'S System, he did not propose any substitute for it ;
and contented himself with ranking porcellanous, vitreous, and arenaceous shells that
correspond in general form, as distinct Species of the same genus.
The Arenaceous type having been made an object of special study by Messrs. PARKER
* " On the Recent Foraminifera of Great Britain," Introduction, p. xi.
MDCCCLXIX. 5 D
722 DE. W. B. CAEPENTEE AND 1MB. H. B. BEADY ON
and T. EUPERT JONES, they were led to recognize it as having the same fundamental
value in a systematic point of view as the Vitreous and Porcellanous types ; and it was
in accordance with their representations, that, in my " Introduction to the Study of
the Foraminifera " (1862), this type was recognized as characterizing a third great
Primary Division of the group. It was pointed out, however, that " to separate all the
Foraminifera that form Arenaceous shells from those of the Porcellanous and Hyaline
types, to which many of them obviously bear the closest affinity, would be a violation
of the first principles of a natural arrangement ; and yet we shall find that there are
certain generic types in which the sandy texture is a character of great systematic
importance." In certain genera, alike of the Porcellanous and of the Vitreous series,
the surface of the true shell is often covered with an arenaceous incrustation ; but this
is a character that does not justify even specific differentiation. It is only when the
whole thickness of the ' test ' is composed of agglutinated sand-grains, and when " certain
assemblages of forms, constituting well-marked generic types, can be uniformly charac-
terized by the possession of Arenaceous shells, as is the case with Trochammina,
Lituola, and Vahulina" that we are enabled to recognize the distinctive value of this
peculiarity, as marking " a fixed and decided physiological character, the occurrence of
which elsewhere is only occasional or incomplete." It was further pointed out that the
absence of pseudopodial pores in the shells of this group shows their affinity to be
rather with the Porcellanous than with the Vitreous series, notwithstanding the very
close resemblance which some of them present to particular types of the latter (op. cit.,
pp. 46-48).
At the time that the Chapter " On the Principles of Classification " in the Treatise
just cited was passing through the press, I learned with great satisfaction that Professor
REUSS of Vienna, the highest Continental authority upon this group, had fully
accepted the doctrine laid down in my previous Memoirs, that the composition and
intimate structure of the Shell are characters of primary importance in Classification,
and that little value in comparison is to be attached to Plan of Growth ; and that he
had communicated to the Imperial Academy of Vienna a Systematic Arrangement based
on these principles, essentially corresponding with that which I had myself Avorked out
with the assistance of my able coadjutors (Messrs. W. K. PARKER and T. RUPERT JONES),
except in the retention of the distinction between the Monothalamia and the Poly-
thalamia, of the validity of which, however, he expressed himself doubtful*. In this
scheme, as in our own, the essentially Arenaceous types were ranked together in a
distinct group, which, like ourselves, he regarded as allied (in virtue of the absence of
pores) rather to the Porcellanous than to the Vitreous series. And having subsequently
come to the conclusion (which I had explicitly stated in the Chapter just referred to,
52) that the distinction between the Monothalamia and the Polythalamia cannot be
maintained, he so modified his scheme in a " Nachschrift," that it came to present a most
* Sitzungsberichte der Mathcm.-naturw. Classe dor Kaisorl. Akad. dor Wissenschaften ; Bd. xliv., "Wien,
1801, S. 355-396.
TWO GIGANTIC TYPES OF ARENACEOUS FOEAMINIFEEA. 723
singular conformity to that which was contemporaneously set forth in more detail in my
Systematic Treatise. This striking coincidence between the results of the studies inde-
pendently pursued by Professor REUSS and ourselves, has tended, I have good reason for
believing, to procure for them a general reception among Continental as well as British
Zoologists, which they might otherwise have been long in gaining.
The Arenaceous group, thus definitely constituted, was considered by Messrs. PARKER
and T. RUPERT JO^ES as consisting only of one Family, the LITUOLIDA ; under which they
ranked the three Genera Trochammina, Lituola, and Valmdina, each of them possessing
such a wide range of morphological variation, as to present in their aggregate a most
curious series of imitations or ' isomorphs ' of true shelly Foraminifera, Vitreous as well
as Porcellanous. "It is not improbable," I remarked ( 205), "that future research
may add largely to our knowledge of these Arenaceous forms;" and this anticipation
has been remarkably confirmed by the results of subsequent investigations. For whilst
a singular variety of recent Arenaceous Foraminifera, some of them of large dimensions,
have been brought up by the Dredging operations which have been lately carried down
to great depths in the Sea, it has been discovered that certain problematical fossils of
very regular globose form, sometimes attaining 2 inches in diameter, occurring in the
Upper Greensand near Cambridge and in the Isle of Wight, and formerly supposed to
be Sponges, are in reality gigantic Arenaceous Foraminifera ; and the like character has
been recognized in a series of fossils which were some time since brought from Persia
by the late Mr. LOFTUS, the striking resemblance of which, both in form and general
characters, to Alveolina, seemed to justify their assignment to the Foraminiferal type,
notwithstanding that their enormous dimensions seemed almost to forbid such a deter-
mination.
Being aware that my friend Mr. H. B. BRADY had made a special study of these
gigantic Alveoline fossils, and had come to the conclusion that they constitute a new and
peculiar type of Arenaceous Foraminifera, to which he has given the generic designation
Loftusia, I thought it likely that he might be able still further to elucidate their structure
by a knowledge of the results I had obtained from the examination of the non-infiltrated
specimens of Parkeria, which I accordingly communicated to him. My anticipations
were so abundantly justified by the results of Mr. BRADY'S re-examination of the minute
structure of Loftusia under the new light thus reflected on it (so to speak) from Parkeria,
that I at once perceived that it would be to our mutual advantage that the descriptions
of these two extraordinary types should be associated in one Memoir ; and on proposing
this to Mr. BRADY, I immediately obtained his cordial acquiescence. For the descrip-
tion of Parkeria, therefore, I hold myself responsible, as Mr. BRADY does for that of
Loftusia ; but each of us has verified all the more important parts of the description
given by the other.
It will be found that both these organisms depart so widely in general plan of struc-
ture from any Foraminiferal type previously known, that they must for the present be
ranked entirely by themselves. If only infiltrated specimens of the Cambridge fossil
5o2
724 DR. W. B. CARPENTER AND ME. H. B. BEADY ON
had come under my examination, or if my sections even of the non-infiltrated examples
had not happened to display the unquestionably Foraminiferal characters of their
central " nucleus," I should have hesitated in referring them to that type on any other
ground than the impossibility of finding a place for them elsewhere, so anomalous is
the structure of the concentric layers by which the " nucleus " is surrounded. It may
be anticipated, however, that when the attention of Palaeontologists shall have been
drawn to these fossils, a much larger variety of Arenaceous Foraminifera will be
brought to light, some of which may connect the anomalous Parlceria and Loftusia
with types already known. And looking to the remarkable results recently obtained
by Deep-Sea Dredging, especially in regard to the persistence, in the deeper parts of
the Atlantic Ocean, of Cretaceous types supposed to have long since become extinct*,
it scarcely seems too much to anticipate that the more extended prosecution of this
inquiry may make known to us living examples of the same group, by the study of
which the relationships of Parlceria and Loftusia may be completely elucidated. For
the present, therefore, I deem it better to abstain from any attempt to assign to them a
Systematic rank, which can at best be only provisional.
PARKERIA.
1. More than twenty years ago, there were found by Professor MORRIS, in the Upper
Greensand near Cambridge, a number of solid globular Calcareous bodies, about an inch
in diameter ; the superficial markings on which suggested both to himself and to Pro-
fessor T. RUPERT JONES the idea that they represent a peculiar type of the Sponges so
common in that Formation. And although the appearances presented by sections of
these fossils did not correspond with the structure of any known Sponge, either recent
or fossil, yet they did not suggest any other interpretation ; and the question of their
nature remained unsolved, until the discovery, between two and three years since, of
two specimens which retain their original Arenaceous condition without any material
change. The partial display of the peculiar internal structure of one of these by a
superficial fracture, having led Professor MORRIS to suspect that they might constitute
a new and remarkable type of Foraminiferal organization, he kindly placed both the
specimens in my hands for examination, together with a number of previously collected
specimens solidified by infiltration ; giving me full permission to treat them in any way
I might think most desirable for the complete elucidation of their characters. And on
his surmise proving well founded, he gladly accorded with me in giving to this type a
Generic designation which should connect with it the name of our valued friend and
coadjutor Mr. W. K. PARKERf .
* Sec my " Preliminary Report " of the Lightning Expedition, in the Proceedings of the Royal Society for
December 17, 1868, p. 192.
t Since the above was written, I have learned that Mr. HAEBY SEELEY, the Curator of the Woodwardian
Museum at Cambridge, had been for several years acquainted with the fossil type I am describing, and had
paid considerable attention not only to its internal structure, but also to what he believes to be its spccifif;
TWO GIGANTIC TYPES OP AKENACEOTJS FOEAM1NIFEKA. 725
2. General Characters. In the two specimens which retain their original Arenaceous
condition, the sphere, when laid open, is seen to be formed of a series of concentric layers
(Plate LXXIL), composed of lamellce of 'labyrinthic structure'*, partially separated
by concentrically disposed interspaces, but connected at intervals by ' radial processes '
which consist of large tubes that are surrounded (in all except the five or six innermost
layers) by labyrinthic structure resembling that of the concentric lamella?. As every
part of the fabric is made up of sand-grains cemented together, it is very easily cut by
a fine saw in any direction, so as to display in section the general structure and arrange-
ment of the arenaceous framework. As such sections, however, are very friable, they
cannot be made transparent enough to exhibit the details of their structure, except by
cementing them to glass with hard Canada balsam (which should be made to penetrate
them thoroughly), and grinding them down after having been thus solidified; and the
specimens thus prepared are by no means equal to transparent sections of the best
infiltrated specimens ( 3, 13). But some of the most valuable information afforded
by non-infiltrated specimens is to be obtained from the examination of fractured sur-
faces ; the concentric lamella? being readily separable from one another by the intro-
duction of a knife-blade into the interspaces. It has been by combining the information
obtained through both these methods, that my able draughtsman, Mr. A. HOLLICK,
has constructed the ideal representation given in Plate LXXIL f ; which brings together
in their actual relations the surfaces obtained by section and by fracture, which are sepa-
rately represented on a larger scale in Plates LXXIII. and LXXIV. ; exactly as they
would be seen if it were possible to remove just those portions of the fabric (and no more)
whose absence is necessary to disclose them.
3. In a second set of specimens, the original Arenaceous framework has been entirely
consolidated by mineral infiltration, which has completely filled all its vacuities : the
infiltrating material is usually calcareous ; but in one remarkable specimen belonging
to the Museum of Practical Geology in Jermyn Street (which I have been enabled to
variations. On communicating with him on the subject, I have received from him a ready acquiescence in the
Generic designation above proposed ; whilst, at the same time, he prefers to reserve the publication of the
results of his own studies of this type, until after the appearance of my description of it. The series of speci-
mens contained in the Woodwardian Museum presents a very considerable diversity of external forms ; but so
far as I have had the opportunity of examining their internal structure, their agreement with the globular type
on which my own'description is based is so complete, as to lead me to regard that diversity as a mere varietal
modification.
* The term labyrintJiic structure has been used in my ' Introduction to the Study of the Foraminifera ' to
denote an irregular aggregation of minute cliamberlets freely communicating with each other ; such as would
be produced by the more or less complete subdivision of a. principal chamber by the growth of partitions inter-
secting one another in various directions, as often happens, for example, in the Arenaceous genus Lituola (op.
cit. 214). This kind of structure presents a considerable resemblance to that which, in the Anatomy of higher
Animals, is termed ' cancellated.'
t Such ' built-up ' figures were very successfully designed by my former draughtsman, Mr. GEORGE WEST,
in his admirable illustrations to my previous Memoirs on this group.
726 DE. W. B. CAEPEXTEE AND ME. H. B. BEADY ON
examine by the kindness of Mr. ROBERT ETIIEKIDGE), the infiltrating material is siliceous.
In either case it is instructive to examine sections made sufficiently thin to be capable
of being viewed under the Microscope by transmitted light ; but whilst in the specimens
in which the infiltrating material has been calcareous, it has usually blended with the
arenaceous framework in a degree sufficient to obscure the precise boundaries of the
latter, in the specimen solidified by silex each individual sand-grain can be distinguished,
and the 'labyrinthic' structure is admirably displayed (Plate LXXVL). The reason of
this difference is probably to be found in the composition of the Sand of which these
fabrics were constructed ( 7).
4. In a third set of specimens the solidification is partial only, the infiltration having
extended from without inwards through a greater or smaller number of concentric
layers ; and in these the original Arenaceous framework of the unconsolidated interior
has for the most part disappeared, so that the spheres, when laid open, are found to be
hollow, the central cavity being occupied only by loose sand-grains, or being altogether
void. In such specimens the consolidated portion is usually very dark and opaque, so
that sections can with difficulty be rendered thin enough for being viewed by trans-
mitted light. It is worth notice that in one of these specimens of which the outer layers
have been completely consolidated, these are succeeded by partly unconsolidated lamellae,
and these again by another set of lamellae whose consolidation is complete ; and this
alternation repeats itself twice as we pass inwards to the central vacuity, which in this
instance has a diameter only about one-fourth that of the entire sphere.
5. The diameter of the largest Parkeria which I have seen (this being a specimen
from the Isle of Wight, in the British Museum) is exactly 2 inches ; that of the smallest
(the silicified specimen in the Museum of Practical Geology) is "75 inch. Other speci-
mens range between these two extremes; the average diameter of those I have seen
being somewhat less than an inch.
6. The External Surface of the silicified specimen is covered with small rounded ele-
vations separated by intervening depressions, so as closely to resemble that of a mul-
berry (Plate LXXIL); and I am disposed to believe that this is the normal condition of
the fabric, the dissimilar kinds of surface presented by other individuals being probably
the result of abrasion. Thus in one of the specimens in my possession, which has not
been solidified by infiltration, the summits of the tubercles have been worn off by
abrasion, so as to lay open their labyrinthic structure, the surface of the depressed por-
tions remaining unbroken ; whilst in another, which has undergone infiltration, the sur-
face is everywhere uniform, as if the tubercles had been rubbed down to the level of
the intervening depressions. In some other cases, however, a condition of surface pre-
cisely the reverse of the first is observable, the rounded elevations being replaced by de-
pressions which are separated by elevated ridges : and this seems to depend upon the
consolidation of the originally depressed portions by infiltration, whilst the tubercles
and the areolae from which they rose continued uninfiltrated ; so that abrasion would
have the effect of wearing down the latter (as the more friable substance) even below
TWO GIGANTIC TYPES OF AREXACEOUS FORAMINIFEEA. 727
the level of the former, and would thus cause the solidified portions to project as ridges.
That the infiltrating material might more readily penetrate the substance of the de-
pressed portions than that of the tubercles, will become evident when it has been shown
that whilst the latter is the most solid portion of the fabric, being minutely labyrinthic
throughout, the former is composed of a mere layer of labyrinthic structure, having
large cavities beneath it (see 17).
7. Although I have spoken of the Material of which these fabrics are mainly com-
posed as ' sand,' yet its composition is very peculiar. When a portion of a non-infil-
trated specimen is treated with very dilute Nitric acid, a slight effervescence takes place,
and the arenaceous particles fall asunder. But when these are treated with stronger
nitric acid, by far the larger proportion of them is dissolved ; only a small residue
remaining insoluble in the strongest acid. Hence it appears (1) that the Arenaceous
particles are held together (as in many other Arenaceous Foraminifera) by a cement
of Carbonate of Lime, which, however, forms no large proportion of the whole ; and (2)
that, although Siliceous sand-grains do occur in small proportion, the principal part of
the Arenaceous material is not siliceous, but (being soluble in moderately strong nitric
acid) is probably Phosphate of Lime. This proves, in fact, to be the case ; a careful
analysis, made under the direction of Mr. H. B. BEADY, having given the following
results :
Phosphate of Lime 59'7
Carbonate of Lime 26 -
Silica 9-0
Iron and Alumina 0-9
Magnesia, Manganese, Organic Matter, &c. ... 4- 4
100-0
8. In several of the specimens which have been partially or completely infiltrated, the
chamberlets and sometimes even the large interspaces of the external layers are occupied
by a substance which presents a green colour alike by transmitted and by reflected light :
this probably consists of the Silicate of Iron, Alumina, and Magnesia, of which the
ordinary green particles of the Upper Greensand Formation are composed, these par-
ticles, as Professor EHRENBERG* has shown, being really the chamber-casts of Foramini-
fera whose calcareous shells have entirely disappeared.
9. Internal Structure. Proceeding now to the details of the internal structure of
these singularly fabricated bodies, we shall find it convenient, as in the case of the dis-
coidal OrbitoHtcs (Philosophical Transactions, 1856, p. 194), to distinguish between the
Nucleus and the Concentric Layers that surround it.
10. The Nucleus, as shown in situ in Plate LXXII., and on a larger scale in Plate
LXXIII. (divided transversely in fig. 1, and longitudinally in fig. 2), is composed of a
series of chambers, c'-c 5 , which are laid end to end in a rectilineal direction ; the series,
* " Ueber dcr Griinsand und seine Einliiuterung dcs organischcn Lebcns," in Abhandlungen der Konig-
lichen Akadcmic der Wissenchaftcn, Berlin, 1855.
728 DE. W. B. CAEPEXTEE AND ME. H. B. BEADY OX
of which the transverse section is somewhat elliptical, having apparently commenced at
the small extremity, and having very gradually widened until it ended abruptly at d*.
The chambers are separated by septa, each composed of a single layer, which are ex-
tremely sinuous, like those of many Ammonites. Of the mode of communication between
the chambers, I am unfortunately not able to speak ; for although, by a happy accident,
the sections of the only two uninfiltrated specimens yet examined, passed through the
nucleus in such a manner as to lay it open transversely in one and longitudinally in the
other, the portions of the septa traversed by the aperture are not exhibited in either
both the chamber-walls and the intervening partitions appear so perfectly homogeneous
in texture, even under a magnifying-power of 80 diameters, that I was at one time in-
clined to regard them as composed of proper shell-substance, corresponding with that of
the Porcellanous Foraminifera, and free from any admixture of arenaceous particles,
its soft and friable texture bearing a close resemblance to that of the fossil Orbitolites
of the Paris Basin. As the like appearance, however, is presented by the walls of the
' radial tubes,' which I have found to have the same Arenaceous composition as the re-
mainder of the fabric ( 14), I am now disposed to believe that the chamber-walls of
the Nucleus are not exceptional in any other respect, than in the fineness of the parti-
cles by the aggregation of which they have been built up.
11. The general aspect of the Concentric Layers enclosing the Nucleus, as presented
by a section whose plane passes through the centre of the sphere (Plate LXXIL), bears
some resemblance to the median plane of an OrMtolite laid open by the removal of one
of its superficial layers. (See Philosophical Transactions for 1856, Plate V., fig. 6.)
But this resemblance diminishes on a closer comparison ; and disappears entirely when
the details of the structure are examined with adequate magnifying-power. For whilst
in Orbitolites the vacuities are chambers, symmetrically arranged in annular series, and
communicating with each other by a regular system of circular galleries and radiating
passages, which traverse the intervening solid shell-substance that forms the walls of
those chambers, the vacuities in Parkeria are merely irregular interspaces left between
successive lanwllce, each of which is composed of a 'labyrinthic' or cancellated sub-
stance, made up of minute chamberlets separated by irregularly-disposed partitions, but
freely communicating with each other ; and these vacuities are traversed by radiating
tubes, which establish a direct communication between the ' labyrinthic system ' of each
layer, and that of the layers internal and external to it. Each of the concentrically
spherical lamellae of labyrinthic substance, together with the interspace (traversed by
* There is probably considerable variety in the disposition of the chambers of the Nucleus. In some speci-
mens from the Isle of "Wight (contained in the British Museum), which, by the kindness of Mr. WOODWAED, I
have had the opportunity of minutely examining since the above was written, the chambers are more numerous,
and the axis of growth is not rectilineal but spiral and in the largest of these specimens the spire actually
turns back on itself. The precise correspondence in structure between the Concentric Layers of these specimens,
and those of the specimens described in the text, leaves me in no doubt that the direction of the axis of growth
of the Nucleus has no essential significance.
TWO GIGANTIC TIPES OF ARENACEOUS FORAMIX1FEEA. 729
the ' radial tubes ') which separates it from the lamella that encloses it, may be conve-
niently considered as one layer ; and it will be found to be entirely on the differences in
the proportions of these two components, that the diversities of aspect presented by the
several parts of the sectional plane depend. Thus it will be observed in Plate LXXIL,
and on a larger scale in Plate LXXIII. fig. 1, that in the twelve concentric layers which
surround the ' nucleus,' the breadth of the interspaces is twice or thrice the thickness
of the solid lamella? ; but that in certain parts of the outer four of these layers, the
solid lamella; send irregular 'processes' across the interspaces, so that the 'labyrinthic
systems' of successive lamellae are brought into connexion not merely by the ' radial
tubes,' but by direct continuity of cancellated structure. These layers are surrounded
by a layer (I 1 , I 1 ) of labyrinthic structure unbroken by any interspace, which is equal in
thickness to any two of the layers it encloses. We then come to a second series of
twelve layers, of greater thickness than the first ; the increase being due to the greater
development of the 'labyrinthic system' of each lamella, whilst the breadth of the in-
terspaces remains the same ; so that the breadth of the interspaces and that of the solid
lamella? are now nearly equal. But we here notice that the interspaces, instead of being
traversed by the irregularly disposed ' radial tubes ' of the inner layers, are crossed at
pretty regular intervals by ' radial processes ' of labyrinthic substance, which (as will be
shown hereafter) form an investment to the radial tubes ; and thus the concentric inter-
spaces that separate the successive solid lamella? from the lamella? internal and external
to them, are divided into a number of small cavities having little communication with
each other. This series of layers is separated by a second thick lamella (P, P) of laby-
rinthic substance, the breadth of which somewhat exceeds that of the first. And around
this is a third series of seven concentric layers, which closely resemble those of the
second, except that the radiating bands of labyrinthic substance are broader, so that
the interspaces which they cross and divide form in the aggregate but a yet smaller
proportion of each layer. The thick lamella (I 3 , / 3 ) of labyrinthic substance which
encloses these, the five ordinary layers by which it is invested, and the yet thicker
lamella (l\ I*) of labyrinthic substance which forms the exterior of the sphere, corre-
spond in all essential particulars with those already described.
12. Thus we see that in passing from the centre to the circumference of the sphere,
we meet with a progressive increase in the proportion which the comparatively solid
'labyrinthic system' bears to the 'interspace-system' of the successive layers; so that
the solidity of the fabric as a whole augments with its increase in size. And this seems
to be a general character of the type ; although there is found to be no constancy, when
different individuals are compared, in regard to the number of ordinary layers that inter-
vene between the peculiarly thick lamella? by which the general regularity of the former
is interrupted.
13. We shall now examine, in more detail, such a portion of a group of Concentric
Layers about halfway between the centre and the periphery of the sphere, as may be
taken to present the plan of structure characteristic of the fabric generally ; after the
MDCCCLXIX. 5 E
730 DE. W. B. CARPENTER AND ME. H. B. BEADS' ON
study of which it will be found more easy to understand the variations from this plan
that present themselves (1) in the ^/?rs-formed layers which immediately surround the
nucleus, and (2) in that last-formed layer which constitutes the exterior of the fully-
developed sphere. Such portions are shown in transverse section, as seen by reflected
light under a power of 25 diameters, in Plate LXXIII. figs. 3, 4 ; whilst another portion
that combines certain features presented separately in the two preceding, is shown in trans-
parent section, by transmitted light, under a power of 70 diameters in Plate LXXVI. fig. 1.
In the latter of these figures, to which the attention may be most advantageously directed
in the first instance, is seen a succession of four lamellae (I 1 1 1 , l*l 2 , I 3 l 3 , Z 4 / 4 ) of labyrinthic
substance, separated in the middle portion of the figure by interspaces which are for the
most part wider than the lamella? themselves, but continuous with each other on either
side. Each lamella is bordered on its inner or ceutrad aspect by a continuous floor (fl*,
f?-,f?,fl*} composed of adherent sand-grains; which completely closes-in the labyrinthic
structure along that face, and cuts off its chamberlets from the contiguous internal in-
terspace, as is yet more distinctly seen in another transparent section which crosses the
interspaces in the contrary direction (Plate LXXV. fig. 1), and in the opaque sections
(Plate LXXIII. figs. 3, 4). On this floor are built up (so to speak) the partitions which
intervene between the chamberlets ; but these are so far from being complete, that the
cavities they surround remain in free communication with each other. There is gene-
rally to be observed, just above the floor, a row of openings more regularly arranged than
those seen elsewhere (as is best shown in Plate LXXIII. fig. 3) ; and the disposition of
these seems to indicate that they are the cross sections of. passages running at right angles
to the plane of section, like the longitudinal galleries which form the communications
between the contiguous series of chamberlets in Alveolina. (See Philosophical Transac-
tions, 1856, Plate XXIX. fig. 8, bb, cc.) The partitions between the chamberlets,
which are composed (like the floor) of sand-grains cemented together, have a generally
vertical (or radial) direction ; but they show no such regularity as would enable it to be
said that they are arranged on any definite plan. They are not covered in by any layer
corresponding to their floor ; so that the chamberlets open freely into the interspace
above; and as this lies on their peripheral aspect, they must have been similarly open to
the surrounding medium, when the layer of which they form part constituted the ex-
ternal surface of the sphere. The contrast between the open or external surface of each
layer of labyrinthic structure, and its closed or internal surface, is best displayed by con-
centric fractures separating two contiguous layers ; as shown in Plate LXXIV. figs. 1
and 2, 3 and 4, of which a detailed description will be found in the next paragraph.
14. It has been already pointed out, in the account of the general structure of Par-
Jceria ( 11 and Plate LXXIL), that the interspaces between the successive lamellae are
traversed by radial processes composed of labyrinthic structure resembling that of the
lamellae themselves; which bring the 'labyrinthic systems' of several successive lamella?
into continuity with each other, as is shown at rp, rp, r^/, r'p', in the highly magnified
section represented in Plate LXXVI. fig. 1. It is only by concentric fractures, however,
TWO GIGANTIC TYPES OF AKEXACEOUS FOEAMINIFEEA. 731
whereby the opposed surfaces of the lamellae are separated from each other, that the form
and arrangement of these 'radial processes' can be properly studied; and the appear-
ances presented by the surfaces thus exposed are found to vary, according as the plane of
fracture has passed through the middle of the interspace, or nearer to one of the Iamella3.
The former has been the case with the pair of lamellaj of which portions of the opposed
surfaces are shown in Plate LXXIV. figs. 1,2; the latter with the pair of which the
outer lamella, carrying with it the 'radial processes,' is shown in fig. 3. In fig. 2, which
represents the external surface of part of a lamella thus detached, we see the labyrinthic
structure- Z, I, opening freely into the interspaces; whilst these cavities are separated by
a set of projections (rp, rp] more or less rounded in form, but connected with each other
by bridging extensions. These are the ' radial processes,' which have been broken across
and laid open by the fracture. The converse aspect is shown in fig. 1, which represents
the internal surface of the lamella that immediately surrounded the preceding ; for its
deeper parts, which constitute the peripheral boundary of the interspace, are here co-
vered by an uniform floor, fl, fl, that cuts them off from the labyrinthic substance be-
neath ; whilst the radial processes rp, rp, which rise as elevations from this floor, are
here less connected together, so that the interspaces form a more continuous system.
The interior of the 'radial processes' thus laid open by transverse fracture is found to
consist of labyrinthic structure rather coarser and less regular than that of the lamella?
they connect ; but in each of them there is at least one large aperture, whilst not un-
frequently there are two or even three ; and these are the cross sections of ' radial tubes '
exactly corresponding with those which are seen in the inner layers (Plate LXXIII.
figs. 1, 2) without any investment of labyrinthic substance. These 'radial processes'
have not unfrequently a somewhat conical form, the apex of the cone being applied to
the outer surface of the enclosed lamella? (with which its connexion is consequently
slight) ; whilst its spreading base becomes continuous with the inner surface of the
investing lamella?, into the labyrinthic system of which its own cancellated structure
opens. Hence, when the plane of fracture passes through the apical portions of the
cones (where the resistance to the disruption of the layers is the least), the ' radial pro-
cesses ' remain in connexion with the investing lamella, as shown at rp, rp, Plate IxXXIV.
fig. 3 ; where are also seen the continuous floor, fl,fl, that cuts off its labyrinthic system
from the interspace on its internal aspect, and the orifices, t, t, of the radial tubes laid
open by the fracture.
15. When, however, as sometimes happens, the concentric fracture passes through the
thickness of a lamella, instead of through the interspaces and the radial processes which
cross them, its labyrinthic system is laid open in the manner shown at Plate LXXIV.
fig. 4 ; where we also see its chamberlets opening into the cavities of the ' radial tubes'
t. t, t, which pass into its substance. This connexion, however, is best brought into
view when these tubes are laid open longitudinally, either by fracture or by section ; as
in the fractured surface shown in Plate LXXIII. fig. 4 ; where we see that the cavity of
the tube t is formed (so to speak) by the coalescence of passages from the labyrinthic
732 DE, W. B. CABPENTEE AND ME. H. B. BEADY ON
system which surrounds its base ; and still better in the transparent section represented
in Plate LXXVI. fig. 1, where two of the interspaces are seen to be traversed by ' radial
tubes' t l , t 2 , which do not form part of the ordinary 'radial processes.' A careful exa-
mination of the entire section of which only a small part is here figured, has fully satis-
fied me of the universality of this communication ; notwithstanding that (as at the upper
part of the tube t, Plate LXXIII. fig. 4) it often appears to be interrupted, the fracture
or section not having happened to lay open the apertures or passages of connexion. And
further, I have been enabled to satisfy myself, by the use of adequate magnifying power,
that notwithstanding the smooth shelly aspect which the walls of the ' radial tubes' often
present, they are in reality built up, like the lamellae between which they pass, of aggre-
gated sand-grains, a fact which may be regarded as justifying the like interpretation of
the appearance presented by the substance of the Nucleus ( 10).
16. When a sufficiently high magnifying-power is applied to transparent sections
thin enough to bear it, so as to bring into view the forms of the individual sand-
grains and the mode of their aggregation, a curious diversity is observable as to both
these particulars between different individuals. In the two non-infiltrated specimens
I have thus examined, the sand-grains are angular, and are fitted together with marvel-
lous exactness, as shown in Plate LXXV. fig. 2 ; in which we see, moreover, that each
of the partitions, p, p, which separate the chamberlets c, c, is formed of at least three
layers of apposed sand-grains. In the specimens which have undergone calcareous in-
filtration, the forms of the individual sand-grains cannot be clearly made out ; but in
the thickness and solidity of the partitions between their chamberlets. they agree with
the preceding. In the specimen which has undergone siliceous infiltration, however,
of which the general structure as displayed in section has been already demonstrated
(Plate LXXVI. fig. 1), the application of a higher magnifying-power shows that the
individual sand-grains have a somewhat rounded form (fig. 2), and are more loosely
fitted together ; and further, that the partitions between the chamberlets are formed of
only a single layer of sand-grains. Hence the cement furnished by the animal must
have probably borne a larger proportion to the sand-grains obtained from without, than
it did in the spheres of which the component sand-grains are so closely fitted together
that there seems no room for any uniting medium ; and the arenaceous structure of this
individual must have been far less solid and compact than that of any of the other
specimens yet examined. The difference in the form of the sand-grains must have been
pretty certainly due to difference of locality, this specimen not having been obtained
with the others, but forming part of a distinct collection. Whether the difference in
general solidity had any relation to the nature of the material employed, can of course
be only determined by the examination of other specimens whose component sand-grains
exhibit the same character ; but it seems a possible supposition that as the rounded form
of the sand-grains must have required more cement to unite them, a limitation in the
quantity of this cement capable of being furnished by the animal might have prevented
it from aggregating the number of sand-grains which are found in such close apposition
TWO GIGANTIC TYPES OF ARENACEOUS FOEAMINIFEEA. 733
in the more solid fabrics. It is difficult to conceive the means whereby the pseudo-
podial filaments projected by the sarcode-body, which must have been the instruments
employed to collect the sand-grains, were enabled to fit them together with a precision
that could not be exceeded by the most dexterous mason, employed to build up angular
stones of every variety of shape, with the smallest possible quantity of intervening
cement, into a wall of uniform thickness and general regularity of surface. But a
precisely parallel case occurs among existing Arenaceous Foraminifera, as I have else-
where shown*.
17. Notwithstanding the apparently well-marked difference between the structure of
the layers now described, and that of the earliest layers represented in Plate LXXIII.
figs. 1 & 2, we shall find this difference to consist almost entirely in the proportions of
the component structure. The labyrinthic substance in the latter case presents itself
in an almost rudimentary condition, the lamellce being very thin, whilst the interspaces
between them are very wide, the entire thickness of the layers, which are composed of
lamella? and interspaces taken together, being about the same as elsewhere. The width
of the interspaces, and the absence of the labyrinthic structure which elsewhere forms
the 'radial processes,' makes the 'radial tubes' very conspicuous; and they are some-
what more closely set than in the outer layers. The first trace of labyrinthic substance
is seen in the wall of the Nucleus itself, alike in transverse and in longitudinal section
(I, Z, figs. 1, 2, Plate LXXIII.); from this, as from a base, spring a number of hollow
pillars, the ' radial tubes,' whereon the first of the investing lamella? is supported, of
which the cancellated structure is scarcely more developed ; and this again serves as a
base for another set of radial tubes, that support a second lamella in which the can-
cellated structure is somewhat more obvious. In the transverse section (fig. 1), we see
that the earlier layers do not pass completely round the nucleus, their disposition being
somewhat excentric, as is very commonly the case with the earlier zones of Orbitolites
(see Philosophical Transactions, 1856, pp. 217, 218); it will be seen, however, on refer-
ence to Plate LXXIL, that the regularly concentric arrangement is soon established in
this direction. In the longitudinal section (fig. 2), however, the earlier lamella? are seen
to be considerably less complete, enclosing but a small part of the length of the nucleus ;
which does not seem to be encased at both its extremities, until four or five of such in-
complete lamella?, each extending somewhat further than that which preceded it, have
been formed upon the surface of the elongated primordial chambered cone. Proceeding
further outwards, we find the concentric lamella? progressively increasing in thickness,
in consequence of the augmented development of their labyrinthic structure, while the
interspaces are proportionately narrowed ; and we see the labyrinthic system of one
lamella occasionally putting forth irregular outgrowths, which cross the interspaces
(usually clustering round the ' radial tubes'), and become continuous with the laby-
rinthic system of the succeeding lamella. Towards the outer part of this series of layers,
which ends with the first thick lamella (I 1 , Plate LXXIL), not only does the thickness of
* ' Introduction to the Study of the Foramini/era,' 213, and Plate VI. fig. 41.
734 DH. W. B. CAEPENTEE AND ME. H. B. BEADT ON
the labyrinthic substance of the lamella come to equal that of the interspaces, but its
peripheral extensions exhibit increased regularity, and become the 'radial processes'
already described as characteristic components of the subsequently-formed layers.
18. Passing now to the outer or last-formed portion of the sphere, we find it to con-
sist of a solid layer of cancellated substance, resembling the solid layers (I 1 , l\ I 3 , Plate
LXXII.) by which we have seen the regular growth to have been previously interrupted,
but of greater thickness and coarser texture (Plate LXXIV. fig. 5). Its inner surface
is bounded, like that of the ordinary lamellae, by a continuous floor (_/?, fl, fl) which
cuts off its chamberlets from the neighbouring interspaces (int, int) ; but its labyrinthic
system is connected with that of the lamella it encloses by the radial tubes (t, t); and these
seem to extend through nearly the whole thickness of the layer, each being the centre,
as shown in Plate LXXV. fig. 4, of a group of chamberlets disposed around it (like the
cells clustered round the vascular canals in an ossifying cartilage), with all of which it is
probably in direct or mediate communication. If each of these tubes (as appears pro-
bable) served as a centre of growth, conveying a stolon-process of sarcode from the sub-
jacent lamella, it may be readily conceived that the group of chamberlets which surrounds
it would project from the general surface, at any rate during the period of most rapid
increase; and that thus would be produced the tuberculated aspect, by which, as already
stated ( 6), the specimens that seem best to represent the original condition of the
organism are characterized. It may be considered not improbable, however, that the
intervening depressions were subsequently filled up by the groAvth of the cancellated
substance, so as to constitute one uniform surface.
19. The strongly marked dissimilarity between the fabric of Parkena as now described,
and that of any FORAMINIFERA previously known, whether recent or fossil, renders it im-
possible to predicate with certainty what was the precise relation of the sarcode-body of
the animal to its Arenaceous ' test.' Looking to the manner in which the earliest cancel-
lated lamella: are attached to the surface of the original chambered cone, it cannot, I
think, be doubted that the sarcode which occupied the latter spread over its exterior, as
in Foraminifcra generally*; and that it was by this layer of sarcode that the walls of
the first labyrinthic structure were built up. The mode in which each subsequent can-
cellated lamella was formed, however, not in immediate superposition on that which
preceded it, but separated from it by a considerable interspace, and only connected with
it by the ' radial tubes,' is not so easily conceived. That each of these tubes contained a
' stolon-process' from the sarcodic substance of the previous lamella, may be considered
next to certain. And the manner in which the chamberlets of the succeeding lamella
are grouped around the extremities of the ' radial tubes,' seems to indicate that the ex-
tensions of these sarcodic 'stolon-processes' furnished the instrumentality by which the
materials were collected and arranged for rearing the walls of those chamberlets. It is
difficult, however, to conceive (1) how the solid flvor was laid, upon which those walls
were built up ( 13), if this floor was entirely destitute of support from beneath ; and (2)
* ' Introduction to the Study of the Foramimfera,' 33-36.
TWO GIGANTIC TYPES OF AEEXACEOUS FOEAMIXIFERA. 735
how, if the laying of this floor was effected by the junction of peripheral extensions
formed around the extremities of independent ' radial tubes,' its surface should possess
the regular continuity by which we find it characterized. In the somewhat analogous
case of TuMpora musica, it is well known that the transverse lamellae connecting the
polype tubes at intervals, which are formed by lateral extensions from the several tubes
whose vertical growth sustains an occasional interruption at those points, are far from
exhibiting such regular continuity. And with the knowledge we have of the general
indefiniteness and polymorphism that prevails among the various groups included under
the KHIZOPOD type, it seems still less to be expected that the multitude of ' radial tubes'
proceeding from one lamella of ParJceria should all simultaneously cease to extend them-
selves longitudinally, and should give off lateral processes with such perfect uniformity
that their coalescence should form a continuous lamella exactly concentric with the pre-
ceding, though connected with it only by the hollow pillars which traverse the inter-
space. On the other hand it is to be remarked that, as all the chamberlets of each
lamella open freely on its exterior, the surface of that lamella, whilst as yet uninvested
by a subsequent growth, may be presumed to have been covered by a continuous layer
of sarcodic substance, in freest connexion with that which occupied its own labyrin-
thic substance. And it would seem not improbable, therefore, that the continuous im-
perforate floor of the superposed lamella should have been laid by the instrumentality
of this layer upon its own surface ; which must then have been completely cut off by
it from direct connexion with the surrounding medium. Such communication must
thenceforth have been only maintained indirectly, through the ' stolon-processes' occu-
pying the ' radial tubes ;' the extensions of which, spreading themselves out on the ex-
ternal surface of the floor of the new lamella, would build up the walls of the chamber-
lets, and would occupy their cavities, becoming in their turn the base of a new sarcodic
investment of what would then be the external layer of the sphere, which, in due course,
would itself be enclosed by another lamella, of which the imperforate floor would be
modelled on its own surface.
20. The question naturally arises whether each sarcodic layer, when it had com-
pletely floored over the interspace it may be supposed to have filled, continued to occupy
that interspace ; or withdrew itself into the labyrinthic system of its own lamella, and
then projected itself through the radial tubes into the labyrinthic system of the next.
To this question no positive answer can be given, since no recent organism is known,
in which any analogous arrangement exists. But the former of the two alternatives
seems to me the more probable, on the following grounds. If the sarcodic segments
were withdrawn from the interspaces, their place must have been taken by some other
material ; since that a vacuum should have been left, is of course inconceivable. How
air could have found its way into them, is scarcely more conceivable ; since these organ-
isms must have been living, like recent Arenaceous Foraminifcra, on the bottom of the
sea, probably at a considerable depth. If any direct communications had existed be-
tween the interspaces belonging to different layers, and between those of the penulti-
736 DE. W. B. CAEPENTEE AND ME. H. B. BEADY ON
mate layer and the exterior, it might be thought not improbable that these interspaces
were filled with water from without, and constituted a kind of aquiferous system. But
since it may be certainly affirmed that no such passages existed, and that the interspaces
had no other communication with the exterior than through the systems of radial
tubes connecting the labyrinthic systems of successive lamella?, which must certainly
have been occupied by the sarcode-body of the animal, there was no provision for the
admission of water to the interspaces, or, if it did enter to replace the sarcode on its
withdrawal from them, it must have remained stagnant in these recesses. If, on the
other hand, the interspaces remained full of sarcode through the whole life of the
organism, there is no difficulty in comprehending that, though cut off from direct com-
munication with the exterior, the sarcodic segments of the interspaces would share in
the vital activity of the entire composite mass. Knowing what we do of the semifluid
condition of living protoplasm, and of the interchange which is incessantly taking place
between the component particles of the segments, however numerous and segregated
they may be, into which the sarcodic body of one of these aggregate organisms is divided,
there is not the least difficulty in understanding how nutritive material might have been
conveyed through the radial system into the innermost penetralia of the sphere of Par-
eTcria, notwithstanding their investment by any number of concentric layers, however
thick*.
EXPLANATION OF THE PLATES OF PAKKERIA.
PLATE LXXII.
Ideal representation of the internal structure of Parkeria ; the different parts shown
in Plates LXXIII. and LXXIV. (from actual specimens) being here combined so as
to show the relations of those parts to each other. In the upper transverse section,
of which the plane passes through the centre of the sphere, the general arrangement of
the concentric layers around the primordial chamber-cone is displayed ; and the inter-
ruption of the ordinary alternation of solid lamellae and interspaces crossed by radial
processes, by the interposition of the four thick layers W, 1 2 P, I 3 l 3 , and I 4 l 4 , is shown.
The details of the structure of the layers immediately surrounding the chambered cone
are represented on a larger scale in Plate LXXIII. figs. 1, 2 ; and the details of the struc-
ture of the thick layers are shown in Plate LXXIV. fig. 5. In the vertical planes, A
* In my Memoir on Orbitolites (Philosophical Transactions, ] 856, 12, 34) I showed that the entire disk,
however numerous may be the concentric zones of which it is formed, is occupied during life by the sarcodic
body of the animal, which continues to fill even the primordial chamber ; notwithstanding that this chamber
and the zones that surround it are in but very indirect relation with the exterior, through the pores of the
peripheral zone. And since the above was written, I have obtained from the Dcep-Sca Dredgings of the Por-
cupine Expedition (1869) a complete confirmation of the view taken in the text. For on examining the internal
structure of the largest nautiloid Lituolte, I find extensions from each chamber-cavity prolonged into its thick
arenaceous wall ; which thus presents, though in a rudimentary condition, a labyrinthic structure whose relation
to the chamber it surrounds is essentially the same as in Parkeria. ,
TWO GIGANTIC TYPES OF AEEN T ACOL T S FOEAMES1FEKA. 737
shows the internal surface of a lamella separated by concentric fracture, the conical radial
processes remaining attached to it, as represented on a larger scale in Plate LXXIV.
fig. 3 : B shows the appearances presented by a similar fracture which has passed through
the radial processes, so as to lay open their cancellated structure, as represented on a
larger scale in Plate LXXIV. fig. 1 : c shows the result of a tangential section passing
through the cancellated substance of a lamella, as represented on a larger scale in Plate
LXXIV. fig. 4 : D shows the appearances presented by the external surface of a lamella
separated by a concentric fracture which has passed through the radial processes, as
represented on a larger scale in Plate LXXIV. fig. 2 ; and E shows the aspect of sections
taken in a radial direction, so as to cross the solid lamellae and their intervening spaces,
as represented on a larger scale in Plate LXXIII. figs. 3, 4. Magnified 7 diameters.
PLATE LXXIII.
Fig. 1 . Portion of section which has cut the central chambered cone transversely :
s, one of its sinuous partitions ; I, I, the first layer of labyrinthic structure,
built up on its external wall, around which are seen successive layers of the
like structure, separated by interspaces which are traversed by the radial
tubes, t, t, t, t, one of which is seen laid open at if. Towards' the right-hand
side of the figure, the progressive increase in the amount of labyrinthic struc-
ture in each concentric layer is apparent. Magnified 25 diameters.
Fig. 2. Portion of section which has cut the chambered cone longitudinally : c 1 , c 2 , c 3 ,
c 4 , c 5 , its successive chambers separated by sinuous partitions ; cZ, its termi-
nation, with the commencement of the labyrinthic structure shown at 1.
Magnified 25 diameters.
Figs. 3, 4. Portions of sections traversing the concentric layers in a radial direction, so
as to show the manner in which the cancellated structure of each lamella is
built up on a solid layer or floor, fl, which cuts it off from the interspace, int,
beneath it. In fig. 3 the manner in which the interspaces are bounded late-
rally by the radial processes connecting the successive layers is well seen ;
and in fig. 4 two of the radial tubes, t, t, contained in those processes are shown
laid open, so as to exhibit their connexion with the labyrinthic structure.
Magnified 25 diameters. The free communication of the labyrinthic structure
on its outer or peripherad aspect, with the interspace separating each lamella
from that which succeeds it, is well seen in both figures ; the lower margin of
which looks towards the centre of the sphere, and the upper to its periphery.
PLATE LXXIV.
Fig. 1. Portion of the internal surface of a lamella, separated from that whereon it was
deposited, by a concentric fracture which has passed through the radial pro-
cesses rp, rp, in each of which are seen one or more large orifices of the radial
MDCCCLXIX. 5 F
738 DE. W. B. CAEPENTEE AND ME. H. B. BEADY ON
tubes. Klfl,fl is shown the solid floor, cutting off the labyrinthic structure
of the lamella from the interspace which separates it from the previously
formed lamella whereon it rests. Magnified 25 diameters.
Fig. 2. Portion of the external surface of the layer from which the layer represented in
the preceding figure had been removed by concentric fracture : rp, rp, radial
processes ; I, I, labyrinthic structure opening freely into the interspaces.
Magnified 25 diameters.
Fig. 3. Portion of the internal surface of a lamella separated from that whereon it was
deposited, by a concentric fracture passing through the apices of the conical
radial processes, rp, rp, so as to leave them adherent to \\,:fl,fl, the solid
floor, continued over the surface of the radial processes, so as to cut off their
labyrinthic structure from the interspaces they bound ; t, t, orifices of the
radial tubes laid open by the fracture. Magnified 25 diameters.
Fig. 4. Tangential section of a lamella, showing its labyrinthic structure, with the ori-
fices t, t of the radial tubes cut transversely or obliquely. Magnified 25 dia-
meters.
Fig. 5. Radial section of the thick outer layer (Plate LXXII. /"), showing its coarsely
labyrinthic structure, in the midst of which are seen the orifices of radial
tubes, t, t, and which is separated by the solid floor fl,fl, from the interspaces
int, int beneath. Magnified 25 diameters.
PLATE LXXV.
Fig. 1. Transparent section of part of a lamella taken in a radial direction ; showing its
labyrinthic structure cut off on its internal or centrad aspect from the inter-
space int 1 which separates it from the previously formed lamella, by the
interposition of the solid floor fl,fl\ while on its external or peripherad aspect
it freely communicates with the next interspace intf, which is bounded peri-
pherally by the internal floor, fi,fl l , of the next lamella. Magnified 30 dia-
meters.
Fig. 2. Portion of the same section enlarged to 250 diameters, to show the arrangement
of the sand-grains of which the framework is built up : -p, p, p, section of
partitions, enclosing the chamberlets c, c ; fl,fl, part of the floor of the laby-
rinthic structure.
Figs. 3 and 4. Portions of thin tangential sections of lamellae of an infiltrated specimen,
viewed as transparent objects ; showing their cancelli grouped around the
radial tubes, whose orifices are seen at t, t. The interspaces are occupied by
crystals of calcite. Magnified 30 diameters.
Fig. 5. Portion of a thin transparent section of an infiltrated specimen, showing the
appearances it presents under a magnifying-power of 15 diameters. On the
left side the section traverses the layers tangentially; and the labyrinthic
structure of the lamellae, the transverse sections of the radial tubes, and the
TWO GIGANTIC TYPES OP AEENACEOUS FOKAMINIFEEA. 739
interspaces filled with crystals of calcite, are obvious. Towards the right side
the section comes to traverse the layers radially ; and we see the connexion
of the labyrinthic structure of the successive lamellae by the radial processes,
between which lie the interspaces filled with calcite. The solid floors sepa-
rating the superposed lamellae from these interspaces are well seen
PLATE LXXVI.
Fig. 1. Portion of a radial section of a specimen infiltrated with silex, showing the details
of the structure of the concentric layers: l l l\ PI 2 , I 3 l 3 , W 4 , four successive
lamellae, showing their labyrinthic structure, built up on the impervious floors
fl l ifl z >fl 3 ,fl*', and opening above into the successive interspaces int 1 , int 2 , int 3 ;
at rp, r'p' are seen the radial processes by which these interspaces are bounded ;
and at t\ t 2 are seen two of the radial tubes laid open longitudinally.
Magnified 70 diameters.
Fig. 2. Portion of the preceding enlarged to 250 diameters, to show the arrangement of
the component sand-grains.
LOFTUSIA.
21. The extraordinary nature of the remains of FORAMINIFERA discovered within the past
few years in the Palaeozoic rocks of Canada, has in many ways affected previously received
views concerning the testaceous RHIZOPODA. In no respect is this so manifest as in the
increased importance accorded to the whole group, on account of the size of its newly
added members. On the first separation of the Foraminifera from the Mollusca, mi-
nuteness was regarded as a distinctive character of the suborder ; and though it was
found necessary to place the Nummulites in a systematic series, which consisted otherwise
of microscopical organisms, they were looked upon as exceptional, in point both of mag-
nitude and of complexity of structure. The discovery in recent times of specimens be-
longing to larger types, such as those dredged off the coast of Borneo by Sir EDWARD
BELCHER, and subsequently described by Dr. CARPEXTER under the generic name Cyclo-
clypeus*, scarcely excited sufficient attention to affect the general idea that the group
was composed of animals of insignificant dimensions ; and it was not until the announce-
ment and description by Dr. DAWSON, of Montreal, in 1864, of Eozoon Canadense, that
the views of Naturalists became modified as to the size attainable by a class of animals
of so simple an organization. It is perhaps not too much to say that the controversy
respecting the Protozoic, or at least the Animal, origin and characters of the remains of
Eozoon, though eventually centering in questions of minute structure, would never have
arisen at all, but for doubts initiated by the dimensions of the fossil. To those who have
made the lower forms of animals their special study, the peculiar arrangement of the
calcareous shelly layers on an acervuline plan of growth, already well observed in other
types of Foraminifera, whilst it accounts for the irregular and asymmetrical external
* Philosophical Transactions, 1856, p. 547.
5 F2
740 DR. W. B. CARPENTER AND MR. H. B. BRADY ON
contour of the Canadian fossil, equally explains the indefinite extension of the shell-
masses.
22. The addition of Eeceptaculites to the list of probable FORAMINIFERA, and the sugges-
tion that Stromatopora, Archceocyathus, and some other obscure fossils, hitherto regarded
as SPONGES in the absence of any very accurate knowledge of their structure, may find
their nearest allies in the same category, are indications of a field of research from which
great results may be anticipated. At the present moment, therefore, any investigations
tending to throw light on what may properly be termed the gigantic types of Foramini-
fera have greatly enhanced interest.
23. Amongst the fossils collected by the late WILLIAM KENNETT LOFTUS, during his
Archaeological and Geological researches near the line of the Turko-Persian Frontier *,
were certain somewhat obscure bodies, oval or fusiform in shape, and occurring in suffi-
cient abundance to give a special character to the rock in which they were imbedded.
As they bore a general resemblance to some forms of Alveolina, a well-known genus of
Foraminifera, from which, indeed, they seemed to differ in point of size rather than in
any structural peculiarities revealed by a cursory examination, they were assigned by
their discoverer to that genus ; and, having attracted but little subsequent attention, have
been left by Palaeontologists in the same position.
24. In Mr. LOFTUS'S memoirf these fossils are spoken of as specimens " of a gigantic
species of Alveolina 3 inches in length;" but no further mention is made of them. Messrs.
W. K. PARKER and 1. RUPERT JONES, in one of their earlier papers on the " Nomencla-
ture of the Foraminifera" J, make a passing allusion to them. Amongst their notes on
the fossil forms of Alveolina, especially those of the Nummulitic Period, they say, " The
largest we have seen was collected in Persia by the late Mr. W. K. LOFTUS, and is three
inches long and an inch and a half in diameter." The two sentences quoted appear to
comprise all that has hitherto been written on the subject of the present paper.
25. A portion of Mr. LOFTUS'S geological collection was presented, some time after his
decease, to the Museum of the Natural History Society in Newcastle ; and finding
amongst other things a number of examples of this supposed Alveolina, I asked, and
readily obtained, permission of the Committee to make such preparations from them as
might be requisite for the elucidation of their structure.
26. A very slight examination by means of transparent sections convinced me that, not-
withstanding a general similarity in external contour, the internal structure was distinct
in many important characters from either of the previously known genera of fusiform
FORAMINIFERA. In Alveolina the shell-wall is opaque, homogeneous, and Porcellanous ; in
* Mr. LOFTUS'S collections were made in the years 1849-52, during tlie progress of a Joint Commission ap-
pointed by the English, Russian, Turkish, and Persian Governments for the demarkation of the Turko-Persian
Frontier.
t " On the Geology of Portions of the Turko-Persian Frontier and Districts adjoining," by WILLIAM KENNETT
LOFTUS, Esq., F.G.S., in Quart. Journ. Geol. Soc. Lond., August 1855, vol. xi. ; foot-note, p. 285.
J Annals and Mag. Nat. Hist., Ser. 3, vol. v. (1860), p. 182.
TWO GIGANTIC TYPES OF ARENACEOUS FORAMUSTIFERA. 741
Fusulina it is Hyaline and perforate ; whilst in the specimens under consideration it was
found to be of distinctly granular texture, resembling the built-up 'tests' of some of the
smoother Arenaceous types. The obvious conclusion was that these singular fossils were
widely separated in organization from their supposed congeners, and that they belonged
to a new type, which probably bore a similar relation to Alveolina and Fusulina, that
Trochammina (incerta) bears to Cornuspira and Splrillina. At the suggestion of my
friend and colleague Professor T. RUPERT JONES, I propose the generic term LOFTUSIA
for the type, thereby to associate with it the name of its discoverer, my lamented pre-
decessor as Secretary to the Natural History Society of Northumberland and Durham.
27. External Characters. Most if not all of the specimens of Loftusia that have been
brought to this country, bear evidence of having formed part of a hard, compact, Lime-
stone rock, from which they have been separated with the utmost difficulty. Indeed
the process of mineralization in the animal remains, seems to have gone on simultane-
ously with changes in the physical character of the calcareous marl of which the matrix
was originally composed ; and the whole has been converted into a uniform subcrystal-
line mass, resembling some of the "fossil-marbles" of our Carboniferous system, and
capable, like them, of receiving a high polish. The rock is traversed by irregular veins
of white crystalline carbonate of lime, very similar to the material that has displaced
the sarcode in the chambers and cellular portions of the shells. A piece of the lime-
stone with the fossils in situ in the Newcastle Collection (Plate LXXVII. fig. 1) shows the
condition in which they are found. It has apparently been long exposed to the action of
weather, and is thereby a good deal roughened ; but still it shows how large a proportion
of the rock is composed of Organic Remains, chiefly those of Loftusia ; and the course
which the fracture has taken, right through the fossils at whatever angle they happened
to lie, without deviating to follow either their periphery or any of their structural lines,
indicates the determined adhesion which exists between them and the matrix. The
appearance of the specimens that have been roughly separated on the spot, testifies to
the same fact ; for scarcely any of them show an exterior surface that can be regarded
as satisfactorily representing the shell during the life of the animal. The general ex-
ternal features, however, are readily made out ; and we are in no worse position in re-
spect to this, than we were with the analogous genus Fusulina, which until a year or
two ago was only known from the sections of Limestone in which it occurred ; yet the
recent discovery of specimens in a free state has done little beyond confirming the accu-
racy of the conclusions previously arrived at*.
28. In shape the specimens are all oblong or oval ; but they vary considerably in their
proportionate dimensions. Many of the longer ones taper almost to a point at either
extremity (Plate LXXVII. fig. 2); whilst a stouter variety (fig. 3) exhibits obtuse
* [Mr. BEADY here refers to the results I have recently obtained from the examination of specimens of Futu-
Una kindly transmitted to me by Mr. C. A. WHITE, of Iowa, U.S. ; which results conclusively establish the cor-
rectness of the opinion I had founded on the study of less perfectly preserved specimens, that Fusulina belongs
to the Vitreous or perforated series, instead of ranking with Alveolina (as was supposed by Messrs. PARKER
and T. UUPERT JONES) in the Porcellanous or imperforate series. W. B. C.]
742 DE. W. B. CAEPEKTEE AND ME. H. B. BEADT OX
rounded ends and a much shorter conjugate axis. The two largest perfect examples
that have come under my notice* have about the same weight (three ounces) ; and their
dimensions represent fairly, and in by no means an extreme light, the difference in pro-
portion alluded to. Their measurements are respectively 3^ inches by 1 inch, and 2j
inches by 1|- inch. In other words, the proportions between the axis and the transverse
diameter are in the long form as 65 to 20, in the short thick variety as 36 to 20. In both
of these specimens the transverse section is circular ; and others of the same form have
proportionate dimensions ranging between the two. There are, however, some few in
which the transverse section is not circular but lenticular (bi-convex). These are of
smaller size, and resemble an almond in general contour (fig. 4) ; but whether the
peculiarity is the result of compression, or is due to an inequilateral plan of growth,
is not easily determined. I am inclined to attribute it, for reasons which will presently
be given, to the former cause ; the more so as there is no ground for specific or
even varietal distinction in the structure of the interior. It may be remarked in pass-
ing, that a similar or even wider range of variation in external form exists in the iso-
morphous genus Aheolina. In that group may be found every gradation in shape, from
a nearly perfect sphere to a spindle with pointed ends, having a length four or five
times as great as its thickness through the centre. Exceptional specimens of Alveolina,
analogous to the compressed examples of Loftusia above referred to, are occasionally
though rarely to be met with in Tertiary limestones.
29. As might be expected from the nature of the matrix, the exact condition of the
exterior of the test, in respect to inequalities of the surface, ornamentation, or markings
determined by structural peculiarities, is not very readily learnt. One or two of the
specimens which appear to have been enucleated with less disturbance of the superficial
layers than the rest, have a series of tolerably regular furrows, nearly equidistant, tra-
versing the shell from end to end, somewhat resembling the uncut portion of that figured
in Plate LXXVIIL, though more uniform. These depressions are not so sharply defined
nor so deeply excavated as similar lines in the smaller Alveolince, neither have they the
same structural significance. It seems probable that they indicate only alternating periods
of more and less vigorous growth, or that they are dependent on external circumstances.
Arenaceous Foraminifera generally show but little tendency to the surface-ornamenta-
tion common in the Vitreous and Porcellaneous groups ; and there is no reason to sup-
pose that, in the living condition, Loftusia differed materially in superficial texture from
Trochammina. Apart from the longitudinal riblets before described, the exterior may
have been either quite smooth or slightly granular, according to the nature of the sand
of which it happened to be built up, and the proportion of calcareous material which
formed the cement.
30. Internal Structure. Although, in general contour, Loftusia most closely resembles
* A specimen in the Museum of the Geological Society, London, must originally have been somewhat larger
than either of these ; but, as it has had sections cut from it for microscopic examination, its exact dimensions
cannot now be obtained.
TWO GIGANTIC TYPES OF AEENACEOUS FOEAMINIFEKA.
743
the two genera already mentioned, Alveolina and Fusulina, its structural relations may
be best understood by reference to the lower members of the Rotalian series, such as
Planorbulina or Discorbina, or to the still simpler type Inwlutina. This relationship,
though at first sight it may appear far-fetched, becomes obvious upon a comparison of
their various sections. It is only necessary to imagine one of the simple Rotalians
thickened and drawn out at the umbilici, so that what was before a convex disk should
become a cylinder tapering more or less towards the ends ; and the analogy is at once
apparent. The transverse section of a body so constructed would correspond to the
horizontal section of the original disk ; and the ideal diagram B would represent equally
well the arrangement of the principal chambers in the Rotalian types and in Loftusia,
as seen in section. At the same time, the lines indicating the septa have in some
respects a different significance in different cases. In theory the test of Loftusia may
be said to consist primarily of a continuous lamina coiled upon itself, like a scroll con-
stricted at the ends. The space enclosed by this 'primary lamina' is divided into
chambers by longitudinal septa. The septa are of ' secondary ' growth ; that is to say,
they are not continuous with the principal wall or ' spiral lamina,' but are rather offshoots
from it. The chambers separated by the septa are long and very narrow, and extend
from one end of the shell to the other. The septa are not perpendicular to the ' spiral
lamina ' as in Alveolina. but very oblique ; and they often take also a more or less oblique
direction longitudinally. The longitudinal section is in this way somewhat confused,
and less to be relied upon than the transverse, in its bearing upon the form and relation of
the various parts. The chambers are further divided by numerous irregular extensions of
the secondary or septal system, which it may be convenient to regard as subordinate to the
rest. These 'tertiary' ingrowths are generally at right angles to the septa, or nearly
so. The diagrams A, B, and C will make somewhat clearer the general plan of
structure ; but it must be borne in mind that they are purely ideal, and drawn without
reference to scale. The first of the three, A, may be supposed to represent a transverse
section of the spiral lamina, or 'primary' wall; B shows, in addition, the 'secondary'
system to which the septa belong ; whilst C indicates roughly the subdivision of chambers
by the 'tertiary' ingrowths.
A. B. C.
31. We must now consider these various structures seriatim, in relation to the appear-
744 DE. W. B. CAEPENTEE AND ME. H. B. BEADT ON
ances presented by the actual specimens. The process of infiltration, which has in
every instance extended to every part of the organism, has obscured its most important
peculiarities. Fortunately in the discovery of Parkeria, and in the results of Dr. CARPEN-
TER'S researches on this new and most interesting type of FORAMINIFERA, we find a clue to
the reading of several portions that would otherwise have remained unintelligible. Many
of the specimens of Parkeria are completely infiltrated with a subcrystalline mineral,
very similar in physical characters to that occurring in the chambers of Loftusia. But
there are others, which, either from the nature of the matrix, or from the compact
texture of the peripheral layer of the test, contain no such deposit ; but remain, as nearly
as can be judged, in the state of a dead and empty recent shell. In addition to these,
a few examples of Parkeria have been met with partially infiltrated ; only their exterior
layers having been consolidated by mineral deposit. Each of these three sets of speci-
mens has added its quota to the facts upon which the elucidation of a somewhat com-
plex organization depends ; and each has a distinct value in the study of Loftusia. By
comparing the appearance of corresponding portions of the infiltrated and uninfiltrated
test in Parkeria, reliable data are obtained from which to estimate the condition of
Loftusia prior to the filling up of its cavities with inorganic matter. Constant compa-
rison with the less altered type has been found needful, in order to demonstrate the
organization of the more obscure form ; and for the opportunity of pursuing the subject
in this way I am indebted to the kindness of Dr. CARPENTER.
32. The texture of the ' test ' has been stated to be Arenaceous, that is, built up of sand-
grains held together by a structureless calcareous cement. It is only necessary to refer
to it in this place, in so far as it affects the relation of the walls to the sarcode-cavities.
The granules vary considerably in size, but are comparatively much larger than those
from which the investment of Parkeria is formed ; hence in the transparent sections of
Loftusia the texture does not appear so homogeneous, nor is the outline of the laby-
rinthic ingrowths so well defined ; indeed it is obvious that in the recent condition the
interior surfaces could not have had the same smooth finish that is to be observed in the
open portions (' interspaces ') of Parkeria.
33. After careful examination of a large number of sections of Loftusia, made on the
median line in both a transverse and a longitudinal direction, I find no indication of the
existence of a central cavity, or anything resembling the large primordial chamber which
is so usual a character amongst the FORAMINIFERA. The tendency to fill up the interior
of the chambers with shelly ingrowths, which leads to some of the most striking pecu-
liarities of its organization, is manifest from the very earliest period of life. We have
no very young specimens from which to study the condition of the test before it assumes
the form and habit of maturity, except such rare instances as may be found in micro-
scopical sections of the limestone matrix, and these are far from satisfactory. One
section of the rock, figured at Plate LXXVIII. fig. 5, shows, however, amongst other
minute fossils, the transverse section of what I have little doubt is a very young Loftusia(a).
The whole is about -fa in. in diameter, and shows the space enclosed by the first turn
of the spiral lamina, and about half the circuit of the layer immediately surrounding it.
TWO GIGANTIC TYPES OF ARENACEOUS FOEAMINIFEBA. 745
The spiral lamina itself has much the same dense opacity as is presented by older indi-
viduals ; and the interior has, so far as can be made out, a loose, arenaceous texture, which,
with a further deposit of cementing material, might be expected to give the sort of struc-
ture we find at the axis of the mature shell. But in the absence of evidence from speci-
mens in the intermediate stages, much importance cannot be attached to the characters
of a single individual, the original features of which may have been greatly altered in
the process of fossilization.
34. In the fully grown examples, the first circuit of the ' spiral lamina' encloses a space
of variable dimensions, in some cases measuring from -^ to -^5- inch in diameter at the
centre, and from i to J inch in length, more or less ; and the revolutions succeed each
other with tolerable regularity at intervals of -$ to -j inch. From twelve to twenty
revolutions are usually found in an adult specimen ; but twenty-five have been noticed
in one instance, and doubtless even a larger number may occasionally be met with.
35. The ' spiral lamina' or ' primary skeleton,' as it may be regarded, is composed of
almost impalpable calcareous grains closely cemented. It is imperforate, and not more
than from - t Q Q to -g-^y of an inch in thickness. From this extreme tenuity it necessarily
depends for support upon accessory structures.
36. The space enclosed by its first revolution constituting the central axis (Plate
LXXX. fig. 2, c a) is occupied by a mass of shell-substance somewhat resembling in
general features a piece of fine sponge, but not quite uniform in its structure. Quite in
the centre it assumes the form of a network of irregular anastomosing tubes, with the in-
terspaces filled in with shell-substance to a greater or less extent ; but nearer the primary
lamina, the irregularly disposed growths resolve themselves into a more definite series,
and take a uniform direction. The outer portion becomes in fact the commencement
of a system of parallel columnar or tubular processes springing from the inner surface
of the spiral lamina, and having their free ends directed inwards (Plate LXXIX. fig. 1, #,
and fig. 2, a). This system of parallel tubuli may under favourable circumstances be
traced throughout the course of the spiral lamina, except when interrupted by the occur-
rence of septa ; and it forms, as well shown in the figures just referred to, a sort of lining
to its inner surface. The two structures are in such close juxtaposition that they appear
continuous ; and their physiological distinctness is only noticed in exceptional places,
when a minute portion of the sarcode appears to have become entangled between them,
leaving for a short distance the primary lamina free from the accessory skeleton (Plate
LXXIX. fig. 2, b, and Plate LXXX. fig. 3, 1). The nature and extent of the labyrinthic
portion of the layers may be best understood from a longitudinal section taken on a line
very near the periphery, as shown in Plate LXXIX. fig. 1 ; for whilst a central section
presents all the layers in the same aspect, one taken near the exterior bears a different
relation to each consecutive layer. Thus we have about the centre of the figure at c the
transverse section of the parallel processes just described as lining the spiral lamina ;
whilst at a is seen the lateral aspect of the same. Such a section leaves no doubt as to
the tubular character of even the more compact portions of the labyrinthic system.
MDCCCLXIX. 5 G
746 DB. W. B. CAEPENTEE AND ME. H. B. BEADY ON
37. The septa, which divide the space enclosed by the spiral lamina into chambers, are
directly connected with the labyrinthic system, and form a part of the accessory skeleton.
There is no continuation of the primary lamina as an imperforate facing to them, nor
is there any analogous investing organ. The septa are therefore entirely secondary,
and are merely extensions of the labyrinthic system, at regular intervals ; taking a very
oblique direction, and terminating on the outer surface of the preceding whorl. The
end of the shell, where, from the greater depth of the layers, and the gradual thinning
out of the chambers, the septa form a prominent feature, shows most clearly their can-
cellated structure and the sort of connexion that exists amongst them. A magnified
drawing of this region (Plate LXXIX. fig. 3) bears a strong general resemblance to those
portions of Parkeria in which the 'radial tubes' are largely developed, though differing
in several essential characters. Not only are the cancellated structures of the septa
connected, but there is free communication between the adjacent chambers of the same
layer. In other words, whilst the spiral lamina is imperforate, the septa have numerous
perforations which allow the passage of sarcode-stolons.
38. But neither the cancellated structure immediately lining the primary lamina, nor
its septal developments, can be distinguished in any very definite manner from further
ingrowths of subordinate importance, which to a greater or less extent occupy the inte-
rior of the chambers. These ' tertiary ' extensions are of very irregular contour ; and
being usually built up of the coarsest particles, are less easily made out.
39. Thus whilst the ' primary skeleton,' or what may be regarded as such, is simple and
easily understood, the accessory structures are of somewhat complex character, and
present appearances very diverse in different specimens, not only from the variable extent
to which they are developed, but also in their disposition and texture. Some specimens
show scarcely any traces of the accessory skeleton, beyond that already indicated as
lining the spiral lamina and forming the septa ; whilst there are others in which the
sarcode-cavities are to a great degree filled up by its extension into their interior ; but
in either case some portions of the superadded structure in each chamber are prolonged,
until they rest upon its floor. In those specimens which have their cavities least filled
up, the ingrowths take the form of tubular columns, which traverse the chambers in a
radial direction (i. e. perpendicular to the spiral lamina), terminating either on the
septum of the previous chamber, or on the exterior wall of the preceding whorl of
chambers. In others they are more massive and irregular, and appear to be arranged
so as to subdivide the chambers in an incomplete manner into chamberlets. When this
latter condition exists, the intersection of the chambers does not take place at regular
intervals ; but the wide central portion of each is left comparatively open, and the
ingrowths increase in frequency as the sides thin out. Transverse sections of the larger
specimens present to the naked eye an appearance as of dark spots set at very regular
intervals along the spiral band, which on examination are found to indicate the central
larger chamberlets in the successive chambers; that is, the wider portions have the
fewest intersecting shelly growths. The smaller chamberlets at each side are hardly to
TWO GIGANTIC TYPES OF ARENACEOUS rORAMES'IFERA. 747
be distinguished, unless magnified, in the general labyrinthic system. This distinction
of large and small subdivisions is one of degree only, and is not nearly so striking
under the microscope as might have been expected from the appearances presented to
the unassisted eye ; but it nevertheless does exist, and is a means to an end.
40. The 'accessory skeleton' in Loftusia may be regarded as the homologue of the
labyrinthic lamellae in Parkeria ; although there are important differences, the precise
significance of which it is impossible to explain with our present limited knowledge of
the relation of the two types. The most remarkable of these is that in Loftusia the
labyrinthic portions take their rise from the inner surface of the primary spiral lamina,
and are directed inwards, that is, towards the central axis ; whilst in Parkeria the order is
reversed, the corresponding structures presenting their free ends towards the periphery.
Again, the ' radial tubes ' which complicate the labyrinthic system in Parkeria, have no
precise analogy to any portion of the accessory skeleton of Loftusia ; the nearest approach
to anything of the sort being the lines of tubular communication between the septa of
the individual layers, at the ends of the shell, where the layer is thickest ; but here, as
in other parts, the spiral lamina cuts off direct communication between the layers. The
office fulfilled by the accessory skeleton in Loftusia is, I conceive, simply that of a
support to the primary lamina, imparting the necessary solidity to the organism. The
subdivision of the chambers into chamberlets seems to be an accidental circumstance,
and has but little bearing on the general economy of the animal.
41. In considering its fitness for this purpose, the various external relations of the
organism must be borne in mind. It is manifest that the delicate calcareous lamina,
described as the ' primary wall,' would, both from its contour and extreme tenuity, be
utterly insufficient of itself to protect a mass of sarcode three inches long and one inch
in diameter, or to impart that rigidity which, judging from other examples, is necessary
to animals of its class.
42. The layer immediately within the 'primary wall' adds greatly to its strength, not
only from the additional thickness it imparts, but also from the connexion its septal pro-
longations establish between the successive whorls. This portion, however, does not
represent a solid mass ; and the septal portions are further weakened by irregular perfo-
rations for the stoloniferous tubes connecting the sarcode of the adjacent chambers. The
columnar extensions of the shell-substance provide direct vertical support ; and their
distribution on the plan described is that likely to ensure the maximum of strength
combined with economy of material. A longitudinal section whose direction nearly
coincides with the long axis of the chambers (Plate LXXX. fig. 4), shows the primary
walls as parallel lines, and the septa (s, s) as slightly oblique bands diverging in the most
gradual way, and eventually connecting one wall with the other. In the exaggerated
view so obtained, the columnar supports (ts, ts) appear at regular intervals; and
throughout the long narrow ends of the chambers they are very close and massive in
proportion to the space left for sarcode. As the chamber widens, they diminish in fre-
quency and proportionate dimensions.
748 DE. W. B. CAEPENTEB AND ME. H. B. BEADT ON
43. The tubular condition of the principal part of the secondary skeleton has been in-
ferred from the appearances presented by portions of exceptional specimens in which the
infiltration has least obscured the structure. But in the absence of these, there would
have been sufficient evidence to be gained from a close comparison with corresponding
appearances in Parkeria, to demonstrate the general tubularity of the labyrinthic system.
This character is foreshadowed in a group of Foraminifera of much simpler type. I
have elsewhere* described the occurrence \r\ Ellipsoidina (an interesting genus of Fora-
minifera discovered by Professor SEGUEXZA in the Miocene clays of Sicily) of a line of
tubular columns, w"hose only ostensible office is to support a series of chambers which
otherwise would have but little connexion with each other. There is a strong reason
why the accessory skeleton which forms so large a proportion of the entire bulk of the
shell in Loftusia should be built up on a plan that would ensure the greatest strength
with the least weight. The habit of Foraminifera is to live on the surface of the sand
or mud at the bottom of the sea, and recent shells taken from a position entirely beneath
the top of the mud are dead and empty ; in point of fact the animal dies if it is buried
in the sand. It is clear from the nature of the limestone matrix, that the floor of the
sea in which Loftusia lived was a very fine calcareous mud, soft and oozy. Now the
specific gravity of the material of which the skeleton is built is about 2-7; and sarcode
itself may be regarded as but little heavier than water ; so that if, as may be supposed,
the hollow sinuses were occupied by sarcode, it would materially alter the relation between
the specific gravity of the animal and the element in which it lived ; that is to say, the
mass comprising the shell and the sarcode would be of much lower specific gravity than
would be the case were the skeleton solid : hence the animal would be correspondingly
better fitted to preserve its natural habitat. It is not certain, however, that the laby-
rinthic sinuses were occupied by sarcode, or even that the ends projecting into the
sarcode-cavities were open ; and it is still possible that they may have fulfilled some
distinct functional purpose. In the absence of evidence on this point, it is needless to
dwell upon it ; but it is within the range of possibility that the cancellated structure
may during life have formed a sort of water-system, or perhaps may even have been
filled in part with air. These are but surmises that have presented themselves during
the investigation ; but if either condition existed, it would further reduce the general
specific gravity.
44. Physical and Chemical Relations. The condition of this fossil is very unfavourable
for the determination of the elementary physical characters of the original organism,
owing to the completeness of the mineralizing process to which it has been subjected.
The sand of which the test is formed is entirely Calcareous ; and its identity in chemical
composition with the mineral substance occupying the sarcode-cavities renders it impos-
sible to separate or distinguish the two by means of reagents. We learn also from the
study of the different condition in which specimens of ParJceria have been found, that
the infiltration of a substance having the same chemical composition as the test has a
* Annals and Magazine of Natural History, 4 ser. vol. i. p. 333, pi. xiiL
TWO GIGANTIC TYPES OF AKENACEOUS FORAMINIFEKA. 749
much greater effect in obliterating its structural characters, and even in obscuring their
outlines, than the same process when a different material is concerned. Thus the
Calcareous test of Parkeria becomes almost devoid of character when its cavities are
filled with a subcrystalline calcareous mineral ; whilst a specimen having its chambers
occupied by silex has lost none of its distinctive characters. Chemical analysis of the
infiltrated fossil (Loftusia) shows that at least 99 per cent, consists of Carbonate of
Calcium, the remaining 1 per cent, being chiefly siliceous matter, a composition repre-
senting equally well an average sample of the limestone matrix. The test, therefore, is
built up of Calcareous sand-grains, incorporated by a cement of carbonate of calcium.
But although the selective power which seems traceable in some Arenaceous Forami-
nifcra, enabling them to choose certain sand-grains in preference to others*, has no
exercise in respect to the chemical nature of the constituents of the test, there is still
something of the same sort observable in relation to the size and distribution of the par-
ticles which go to its formation. Thus whilst the septa and the looser portions of the
labyrinthic structures are coarsely arenaceous, the spiral lamina is composed of exceed-
ingly minute particles. The presence of a number of specimens of the smaller species
of Foraminifera imbedded by accident with the sand in which they were living, and
now forming a portion of the fabric (Plate LXXX. fig. 3, f,f\ renders it comparatively
easy to estimate the size of the sand-grains. The largest that could be satisfactorily
measured was about y^ of an inch in diameter ; but they seldom attain more than one
half this size. Specimens of the same species abounding in the Limestone matrix run
to much larger dimensions. One of the almond-shaped specimens of Loftusia which
appears to have had its walls somewhat disintegrated by pressure or otherwise, presents
its constituent granules in a very uniform condition, both as to their general appearance
and their dimensions, and in this instance the average diameter is about ^^ of an inch.
In the more compact portions of the labyrinthic system, the granules are smaller; and
as they approach the spiral lamina they become still more minute. In the thin layer
which constitutes the lamina itself, a magnifying-power of 500 diameters (the highest I
have been able to use with advantage on any section yet prepared) shows the ultimate
structure only as a uniform, densely packed mass of particles, individually too small for
even approximate measurement. The transparent sections (Plate LXXIX. figs. 4 & 5)
cross regions in which the constituent granules are exceptionally small and uniform,
and show well their close setting in the compact portions (sg, s(j).
45. The variable external appearance of such of the fossils as have been exposed
through the unequal action of the weather, especially on the fractured surfaces is pro-
* The question of selection of materials amongst Foraminifcra with composite tests is one to which my
attention was drawn in a recent chemical examination of subarenaceous Hil'iola; (Quinqutloculina ayylutinans)
obtained by Mr. JEFFREYS from deep water in the Hebrides. Their tests were clearly formed of sand-grains
and cement. They occurred in siliceous sand, having but a very small percentage of calcareous matter derived
from the debris of Molluscan and other shells ; yet they were entirely soluble in very weak acid, leaving scarcely
a microscopic trace of silica.
750 DE. W. B. CAEPEXTEE AND ME. H. B. BEADY OX
bably due to other causes rather than to the size of the constituent sand-grains, and
chiefly to two, viz. a slight difference in the character of the subcrystalline deposit in the
chambers, and the partial disintegration of the shell-structure from pressure or other dis-
turbing cause, during, or it may be previous to, the process of mineralization. I have
noticed that the specimens in which the exposed portions are the roughest and most
granular, are those in which the structure is most confused, not merely in the labyrin-
thic growths, which are naturally of coarser texture, but even in the compactly built
spiral lamina, which, usually so well denned, is often scarcely traceable in such indi-
viduals.
46. It has been stated that the shells of a number of the minuter forms of Foraminifera
are to be found imbedded in the shelly material forming the test, their presence being
due to the fact of their having been living amongst the sand in the neighbourhood of
the animal whilst the process of building its skeleton was being carried on. Their
identification is of considerable importance, as they afford, together with the organisms
to be observed in the limestone matrix, the only data by which the depth of water wherein
the animal lived, may be indicated with any degree of accuracy. In the test itself the
following have been noticed : in many cases it is impossible to do more than identify the
Genus, specific and varietal characters often depending on peculiarities not to be recog-
nized in sections.
BilocuKna ringem, Lamk. Planularia longa, Cornuel.
Biloculwa contraria, D'Orb. Textularia sagittula, Defrance.
Triloculina oblonga, Montagu. . Textularia variabiUs, Will.
Triloculina trigonula, Lamk. Textularia pygmcea, D'Orb.
Triloculina tricarinata, D'Orb. Sigencrina nodosaria, D'Orb.
Quinqueloculina seminulum, Linn. Discorbina, sp.
Spiroloculina planulata, D'Orb. Eotalia Beccarii, Linn.
Trochammina incerta, D'Orb.
The specimens seen in the limestone rock are generally of much larger size than those
which have been built into the walls of Loftusia itself. Most of the foregoing varieties
occur, and, in addition, the following,
Spiroloculina canaliculata, Czjzek. Sulimina ovata, D'Orb.
Valvulina Austriaca, D'Orb. Planorlulina ammonoides, D'Orb.
Cristellaria, sp. Eotalia Schrceteriana, P. & J.
Dentalina, sp. Nummulina, sp.
The last named is one of the small thick forms characteristic of the lower Tertiary
strata.
47. Mr. W. K. PARKER has given me much assistance in these determinations. The
conclusions to be derived from them are that the rock is a lower Tertiary limestone, very
similar to some of our Miliolite limestones, but richer in the small arenaceous forms ;
TWO GIGANTIC TYPES OF AEENACEOUS FOBAMINIFEEA. 751
t
and that the sea-bottom was a soft calcareous mud, and lay at a depth of from ninety to
one hundred fathoms. A few minute fragments of Molluscan shells resembling columns
of Pinna, and small pieces of fossil POLYZOA, are the only remains that are to be found
of animals of higher organization than Foraminifera.
48. Zoological Relations. From the details of structure which have been adduced, the
genus Loftusia would seem to find a natural place at the head of the Arenaceous series
of Foraminifera, a position corresponding to Alveolina in the Porcellanous group, and
Fusulina amongst the Vitreous forms. In texture it is similar to the higher Trocham-
mince. Its general plan, in so far as the primary skeleton is concerned, is simple ; and
there is no approach to the more complex organization found in the shell of the Num-
mulite or its immediate allies. Its most striking external difference from the other
members of the Arenaceous group (Parkeria of course excepted) is its size; and the
chief peculiarity of its internal structure consists in the secondary shelly growths neces-
sary for the support of the enlarged test.
49. Notwithstanding great diversity in the size and contour of the specimens, their dif-
ference is attributable to degree of development depending on external causes, rather
than to specific or varietal distinction ; and with a slight reservation in respect to the
compressed specimens, I propose to place all under one species, of which the following
will serve as a description.
LOFTUSIA, gen. nov.
Testd lilerd, regulariter rotundatd, axe elonyato ; transverse sectd orbiculari (aut len-
ticulari ?} ; ex spird bene compositd, cujus orbis qidsque orbem antecedentem penitus am-
plectitur, constante ; in numerosissimos loculos septis longitudinalibus partita iterum plus
minusve subdivisos ; structurd arenaced ; aperturis (multis, complexis, labyrintheis?).
L. PEESICA, spec. nov. L. testa elongatd, ovatd vel fusiformi ; transverse sectd orbicu-
lari (vel compressd ?} ; extremitatibus obtusis aut rotundatis ; loculis multis, angustis,
interne cancellatis, cancellis ad axem versis ; septis perobliguis ; aperturis (multis,
compleocis, super facie ultimi loculi arcuatd sparsis ?) ; superficie Icevigatd aut suba-
renaced, interdum sulcis subtilibus paribus intervallis inter se distributis in longitu-
dinem sculptd. Longa, 1-5 usque ad 3'5 poll. Lata '5 usque ad l'2o poll. LOG.
Persia, fossilis.
Distribution. In respect to distribution but little can be said beyond what appears
in Mr. LOFTUS'S Memoir (op. cit., p. 235) and the notes accompanying the specimens
presented to the British Museum and the Geological Society ; but the information from
these sources is deficient both in Geographical and in Geological details. In describing
the geological characters of a section lying " on the direct road between Kalah Tul and
Isfahan," after speaking of a confused series of gypsiferous rocks, which seem ' ; as if the
bed had been shot off the side of Mererari during its sudden elevation," the author adds,
" Masses of gravel-conglomerate lie in the bed of the stream and high up the slopes of
752 DE. TV. B. CAEPEXTEE AND ME. H. B. BEADY OX
the mountain through which the Ab-i-Bazuft flows," and then follows this foot-note :
" A few miles N.E. of this stream (but before reaching the left bank of the Kuran at Du
Pulun) I procured from a hard rock of blue marly limestone a gigantic species of Alveo-
lina, three inches in length." The station appended to the specimens in the British Mu-
seum and the Geological Society is the " Kellapstun Pass, near Du Pulun, Bakhtiyari
Mountains, Persia." Unfortunately scarcely any of the names mentioned appear on the
" Sketch-map" that accompanies the paper ; and for scientific purposes the district referred
to may be said to be as yet unmapped. I am indebted to Mr. KEITH JOHNSTON, of Edin-
burgh, for a detailed tracing of the region, procured with some pains from unpublished
German sources; from which it appears that Du Pulun is on the 32 parallel N. Lat.,
and that a Longitude of 50 30 E. would indicate a point halfway between it and the
little mountain stream Ab-i-Baziift. The district lies between the N.E. corner of the
Persian Gulf and Isfahan.
50. Our knowledge of the Geological distribution of the type may be summed up in few
words. Mr. LOFT us appears to regard the "blue marly limestone" as belonging to the
oldest Tertiary rocks, though he does not say so very distinctly ; and the evidence of the
Foraminifera imbedded in it leads pretty conclusively to the same view. The data
afforded by the Microzoa are probably sufficient confirmation, in the absence of any satis-
factory record of larger fossils from the same geological horizon.
In conclusion I have to express the obligation I am under to my friends Mr. W. K.
PARKER and Dr. CARPENTER, for the interest they have taken in the subject of the pre-
sent paper; to both for suggestions derived from their large knowledge and philo-
sophic views in connexion with the Protozoa generally, to the latter for light thrown
upon obscure points by the study of collateral structures in Parfceria, and above all for
the opportunity of constant reference to specimens of that genus, without which the
history now given could not have been so far elaborated.
EXPLANATION OF THE PLATES OF LOFTUSIA.
PLATE LXXVII.
Fig. 1. Piece of Loftusia-limestone, the surface of which has been ' weathered' by expo-
sure, and the sections of the fossils thereby brought into relief (natural size).
Figs. 2, 3 & 4. Loftusia Persica (natural size). Of these figs. 2 & 3 represent longer
and shorter individuals of the normal form, whilst fig. 4 is the compressed
variety with lenticular transverse section described in 27. Figs. 2", 3", 4"
represent the transverse sections of the three specimens drawn to their natural
size.
Fig. 5. Section of the Limestone rock forming the matrix of Loftusia, with Foraminifera
in situ.
a. Young specimen of Loftusia cut transversely, showing the space enclosed
TWO GIGANTIC TYPES OF AEENACEOTJS FOKAMINIFEKA. 753
by the first turn of the spiral lamina, and about half the circuit of the
layer immediately surrounding it.
Sections of several other Foraminifera included in the matrix are seen.
PLATE LXXVIII.
General view of the structure of Loftusia, showing the appearances of sections cut on
different planes, and their relation to each other. Magnified about 4 diameters.
PLATE LXXIX.
Fig. 1. Longitudinal section of Loftusia, very near the periphery, viewed as an opake
object. Magnified 45 diameters.
s I. Imperforate primary skeleton or spiral lamina.
a. Series of parallel, columnar, secondary shell structure, immediately
lining the primary lamina.
c. The same cut transversely.
It must be borne in mind that this is not a central section, but a tangential one cut
so near the periphery that the direction of the section differs in its relation to each
successive layer, so as to illustrate fully the arrangement of the accessory skeleton. The
centre, representing the innermost of the four layers of which portions are drawn, shows
at c the appearance presented by the parallel columnar shelly processes (a, a) when cut
across. The portion of the figure to the right exhibits a mass of the accessory skeleton
formed from overlapping septa, and shows the sort of intercommunication between them.
Owing to the direction of the section, or possibly to accidental causes, the spiral lamina
(s I), the continuity of which is usually a prominent character, appears lost at the end of
the layers to the right, though well seen in the other portions of the specimen.
Fig. 2. A portion of a transverse section, s I represents the spiral lamina, and at I its
distinctness from the accessory structures may be noticed. This condition
may be found at points in almost every specimen. The nature of the septa,
as prolongations of the series of columnar processes (a, a, a) lining the pri-
mary lamina, may be easily traced. The subdivision into chamberlets, a
large chamberlet (c c, c c, c c) occupying the centre of each chamber (see 39),
is also apparent. Magnified 45 diameters.
Fig. 3. Longitudinal section of a portion of a layer near the end of the central axis.
At this point, where the layer is widest and the chambers thin out and over-
lap, the intercommunication of the septa is often so regular and complete
that it resembles very strongly the portions of Parkeria in which the system
of radial tubes is most developed.
MDCCCLXIX. 5 H
754 ON TWO GIGANTIC TYPES OF AKENACEOUS FORAMINIFEKA.
Figs. 4 & 5. Transparent sections, to illustrate the nature of the subcrystalline calcareous
deposit filling the chambers, and the close setting of the sand-grains (s g, s g)
in the compact portions of the test. Magnified 45 diameters.
PLATE LXXX.
Fig. 1. General view of a transverse section of an average specimen, mounted in Canada
balsam and seen as a transparent object, under a low power. Magnified 5
diameters.
Fig. 2. A similar preparation from one of the compressed specimens alluded to at 28.
Magnified 6 diameters.
All the almond-shaped specimens are small, possibly not fully grown ; and
if so, the composite test may have been less consolidated than in mature indi-
viduals. This may account for their form. The arrows If, If indicate a line
on which pressure at the two sides appears to have caused the fracture of
many of the layers.
Fig. 3. Enlarged view of a portion of the transparent section shown in fig. 1. Magni-
fied 25 diameters.
s I, si. Spiral lamina.
J, b. Points at which the ' primary ' and the ' accessory ' skeleton are not in
close approximation, and show their distinctness.
f,f,f- Imbedded Foraminifera in situ.
Fig. 4. Longitudinal central section of a single layer near the periphery, showing the
regularity of ' tertiary ' processes subdividing the chambers.
si, s I. Primary skeleton.
s, s. Septa.
t, s. Tertiary shelly processes affording perpendicular support.
Carpenter
LXXli
PARKERIA.
A llollirk del el hill
WW.-til irn,
Carpenter
Phil, flwi&MDCCCLXK: /YnA- 1 JOUI1
A HolKdr del rt lilh.
Carpenter
fe
Phil. TnuuMDCCCLSJLPLate J XW.
2. I
' - I
r-p
'#*"
A.HoIlick del etbtk.
WWesl imp-
Phil. Trams. MD CCCLXDC J'
ABolliokdel etM,
WWrsI ,,,.
Carpenter
I 4
WJH.V^eoiey J,th
W Weotimp.
/ 1W/..ZJWIS.MDCCCLXIX Plate 1 ,XXY!!
3.
'
W Wf :.'
Phil. TTVWS MD CCCLXK-PZote LXXM
o
W
<
H
CO
ck del et lilli
I '/, il Trasis MDCCCLXIX / >lajte I ,XX1X
A.Hollici del et lith
WWe-i
hil. Traun*. MDCCCLXDCPZofc I, XXX
If-
^.4-ft 3s^r33i8w^ Ara.-^
5S-*^*SiU^ *l.
735>iaBR&MfiMaiuitf
^S*^ SSO*
r*i^<i i5--'. /if:, . '-A ) j ..-'/-?A
\ I
}
r ( }) s / )>-*.-
-
-.V :
RETURN
TO
LOANPERIOD
o
2/84 BERKELEY, CA 94720