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GEOLOGICAL SURVEY OF CANADA. 
 
 REPORT 
 
 on 
 
 CANADIAN GRAPTOLITES. 
 
 n 
 
 JAMES HALL, Esq., 
 
 OF ALDANY. 
 
 EXTRACTED PROM 
 
 SIK WILLIAM E. LOGAN'S REPORT OF PROGRESS, 
 
 Fob 1857. 
 
 :Ponttf al : 
 
 PRINTED BY JOHN LOVvll 
 
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 ■• • 09 ■••• • 
 
 V 
 
REPORT 
 
 or 
 
 JAMES HALL, Esq., 
 
 ADDRK3SKD TO 
 
 SIR WILLIAM E. LOGAN, F.R.S., 
 
 DIRECTOR OF THE GEOLOGICAL SURVEY OF CANADA. 
 
 Albany, 1st March, 1868. 
 Sib, 
 
 lu reply to your enquiry regarding the Graptolites 
 and other allied genera, confided to me for description on 
 behalf of the Geological Survey of Canada, partly in 1864, 
 and partly at a subsequent time, I have the honor to inform 
 you that six plates of the Graptolites have been engraved, 
 and are now only waiting to be lettered, and that drawings 
 for ten more plates are in the engraver's hands. 
 
 The description ot twenty-four species accompanies the pre- 
 sent communication, and the plates will follow as fast as 
 they are completed. 
 
 » 
 
In April 1865, 1 communicated to you a note upon thes« 
 remarkable Graptolitcs, discovered in the progress of the 
 Geological Survey during the previous year. This discovery 
 gave for the first time a knowledge of the true forms and mode 
 of growth of these fossils, of which fragments and detached 
 branches have for so many years been described as complete 
 forms. Neither up to that time, nor so far as 1 am aware 
 to the present, has any evidence of the existence of perfect 
 forms such as these been given to the public. 
 
 Two of the species were described in the note transmitted 
 to you in 1855, and I have preceded the description of the 
 remainder by a repetition of that note. 
 I have the honor to be, 
 Sir, 
 Your most obedient servant, 
 
 J 
 
 i 
 
 JAMES HALL. 
 
lies* 
 the 
 
 VCTJ 
 
 lode 
 5hed 
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 vare 
 rfect 
 
 i 
 
 1 
 
 DESCRIPTIONS 
 
 or 
 
 itted 
 ' the 
 
 CANADIAN GEAPTOLITES. 
 
 \ 
 
 I 
 
 L. 
 
 Note upon the Genus Graptolithus, and descriptions of soma 
 
 remarkable new forms from the shales of the Hudson 
 
 River group, diacovered in the investiga ^f 
 
 , Geological Survey of Canada, under the di. 
 
 W. E. Logan, F.R S. By James Hall. 
 
 [Communi'Taicd in 
 
 Sir 
 
 o 
 
 The discovery of some remarkable forms of this genus au*. ^ 
 the progress of the Canada Geological Survey, has given an 
 opportunity of extending our knowledge of these interesting 
 fossil remains. Hitherto our observations on the Graptolites 
 have been directed to simple linear stipes, or to ramose forms, 
 which except in branching, or rarely, in having foliate forms, 
 differ little from the linear stipes. In a few species, us G. tenuis 
 (Hall), and one or two other American species, there is an 
 indication of more complicated structure ; but up to the 
 present time this has remained of doubtful significanc*'. The 
 question whether these animals in their living state were free 
 or attached, is one which has been discussed without result ; 
 and it would seem to be only in very recent times that natural- 
 ists have abandoned altogether the opinion that these bodies 
 belonged to the Cephalopoda. 
 
6 
 
 In the year 1847 I published a smuH paper on the Graptolitea 
 from the rocks of the Hudson River group in New York. To 
 the number there given, two species have einco been added 
 from the shales of the Clinton group. Other species, yel 
 unpublished, have been obtained from the Hudson River 
 group ; and since the period of my publication in 1847, large 
 accessions have been made to our knowledj^e of this family of 
 fossils, and to the number of species then known. The most 
 important publications upon this subject are, Les GraptoUtet 
 de Boheme, par J. Bairande, 1850; Sympsis of the Classifi- 
 cation of British Rocks, ami Dcscnptions of British Palteozoic 
 Fossils, by Rev. A. Sedgwick and Frederick McCoy, 1851 ; 
 Grauwarkcn Formation in Sachsen, c. . by H. B. Geinitz, 1852. 
 
 The radix-like appendages, known in some of our American 
 as well as in some European species, have been regarded 
 AS evidence that the animal in its living state was fixed ; 
 while Mr. J. Barrande, admitting the force of these facts, 
 asserts his belief that oLher species were free. It does not 
 however appear probable that in a family of fossils so clc lely 
 allied as are all the proper Graptolitidcee, any such great 
 diversity in mode of growth would exist. 
 
 It will appear evident from what follows, that heretofore 
 v/e have been compelled to content otn-aelves, for the most part, 
 with describing fragments of a fossil body, without knowing 
 the original form or condition of the animal when living. 
 Under such circumstances, it is not surprifting that various 
 opinions have been entejtained, depending in a great measure 
 upon the state of preservation of the fossils examined. The 
 diminution in the dimensions, or perhaps we should rather 
 say in the development, of the cellules or serrations of the 
 axis towards the base, has given rise to the opinion advanced 
 by Barrande, that the extension of the axis by giowth 
 was in that direction, and that these laller celli were really 
 in a state of increase and development. In opposition to this 
 argument, we could before have advanced the evidence fur- 
 nished by G. hicornis, G. ramosvs, G. sextans, G.furcatus, G. tenuis, 
 and others, which show that the stipes could not have increased 
 in that direction At is true that none of the species figured 
 
by Barrando in.licuto insuperable objections to this view ; 
 though in the figures of G. serra (Brong.), as given by Geiniti, 
 the improbability of such a mode of growth is clearly shown. 
 
 It is no" 1 little remarkable Jmt with such additions to the 
 number of species as have been made by Barrande, McCoy, 
 and Geinltz, so few ramose forms have been discovered ; and 
 none, so far as the writer is aware, approaching in the perfec- 
 tion of this character to the American spv-icies. 
 
 Maintaining as we do the above view of the subject, which 
 is borne out by well-preserved specimens of several species, 
 we cannot admit the proposed separation of the Graptolites 
 into the genera Momgrapsus, Diplograpsus, and Cladograpsus, 
 for tie reason that one and the same species, as shown in single 
 indivii^uals, may be monoprionioean or dlprionidean^, or both ; 
 and we shall see still farther objections to this division, as we 
 progress, in the utter impossibility of distinguishing these 
 characteristics under certain circumstances. We do not yet 
 perc ive sufficient reason to separate the branching fonnsfrom 
 those supposed to be not branched, for it is not always possible 
 to decide which have or have not been rai, jse, among the 
 fragments found. Moreover, there are such various modes of 
 branchinfj", that such forms as G. ramosus present but little 
 analogy with such as G. gracilis. 
 
 Mr. Geinitz introduces among the Graptolitidea the genui 
 Nereograpsif4, to include Ncreites, Myrianites, Nemertitrs, and 
 NemajMdia. Admitting the first three of these to be organic 
 remains, which the writer has elsewhere expressed his reasons 
 for doubting , they are not related in structure, substance, or 
 mode of occurrence, to the Graptolites, at least so far as regards 
 American species ; and the Nemapndia is not a fossil body, nor 
 the imprint of one, but simply the recc7it track of a slug over 
 the surface of the slates. The genu. Rastrites of Barrande 
 has not yet been recognized among American Graptolitidea. 
 These forms are by Geinitz united to his genus Cladograpsm, 
 the propriety of which we are unable to decide. 
 
 The genus GladioUtes {Retiolites of Barrande, 1850, Grap- 
 tophyllia of Hall, 1849) occurs among American forme of the 
 Graptolitidea: in a single specit's in the Clinton group of New 
 
/ 
 
 8 
 
 York. A form analogous, with the reticulattui margins and 
 itraight miiirib. has been obtained from the shales of the 
 Hudson River group in Canada, suggesting an inquiry as to 
 whether the separation of this genus on accouiit of ihe reticu- 
 lated structure alone, can bo sustained. In the mean time we 
 may add that the Canada collection sustains the opinion already 
 expressed, that the Diclyoncma will form a genus of the family 
 Gra'ptolidde<E. The same collection has brought to light 
 other specimens of a character so unlike anything heretofore 
 described, that another very distinct genus will thereby be 
 added to this family. The Canadian specimens show that the 
 Graptolites are far from always being simple or merely branch- 
 ing flattened stems. 
 
 The following diagnosis will express more accurately the 
 character of the genus Graptolithus, as ascertained from an 
 examination of perfect specimens in this collection. 
 
 Gefius Graptolithus, (Linn.) 
 
 Description. — Corallum or bryozoum lixed, (free?) compound 
 or simple, the parts bi-laterally arrang(fd, consisting of simple 
 stipes or of few or many simple or variously bii'urcating 
 branches, rad* iting more or less regularly from a centre, and 
 in the compound forms united towards their base 'r» a continu- 
 ous thin corneous membrane or disk formed by an expansion 
 of the substance of the branches, and which in the living state 
 may have been in some degree gelatinous. Branches with a- 
 single or double series of cellules or serratures, communicating 
 with a common longitudinal canal, aflixed by a slender radix 
 or pedicle from the centre of the exterior side. 
 
 The fragments, either simple or variously branched, liitherto 
 described as species o( Graptolifhus, are for the most part to be 
 regarded as detached portions from the entire frond. 
 
 In the living state we may suppose those with the corne- 
 ous disks, and numerously branched fronds to have been 
 concavo-convex (the uppe- being the concave side), or to have 
 had the power to assume this form at will. In many spe- 
 cimens there is no evidence of a radix or point of attach- 
 
I 
 
 ment, and they have very much the appearance of bodies 
 which may have floated free in the ocean. 
 
 GlUPTOHTIIUS LOGANI. 
 PtATB I. Fig. 1-6, Plate II. Fig. 1-4. 
 
 Description. — Frond comi)Osed of numerous branches nearly 
 equally disposed on two sides of a central connecting stipe, 
 and each again subdividing nearly equally, after which they 
 bifurcate, always near the base, with greater or less regularity; 
 connecting membrane thin, composed of the same substan- 
 ce, and continuous with the branches, extending from the 
 centre to some distance beyond the bifurcations ; the branches 
 after the third bifurcation become marked on the inner side 
 by a row of cellules, and along the centre by an abruptly 
 impressed lino which follows the divarication of the branches; 
 celluler minute, not prominent towards the base of the 
 branches, being compressed vertically, and appearing like a 
 double series with a central depressed line, becoming deve- 
 loped as they recede from the base. The branches beyond 
 the disk are turned on one side and laterally flattened, and 
 present a single series of cellules or serrations, which aro 
 moderately deep, with the serratures acute at their extremi- 
 ties ; from twenty-four to twenty-eight in an inch. The 
 substance of the branches upon the exterior surface near the 
 centre, is marked by a depressed longitudinal line, which 
 follows the ramifications, and gradually dies out as the branches 
 become finally simple, when the surface on the same side is 
 smooth or somewhat obliquely striated. The disk is smooth 
 exteriorly, and from the centre is a sniall radicle from wliich 
 the two sets of branches diverge. 
 
 This species, though in a general manner bi-lateral and 
 presenting four principal branches, is nevertheless from the 
 irregular division of these, usually unequal upon the two 
 sides ; and we find on examination of those figured that they 
 are as ten and ten, nine and eleven, ei{)hfc and nine, ten and 
 eleven, seven and ten, twelve and twelve, eight ind eight* 
 eight and ten, while the half which is figured on Plate II 
 has eleven rays. 
 
to 
 
 Plate I. Fig. I. An individual showing tlie exterior sur- 
 face ; the central portions entire, with the impression of the 
 connecting corneous membrane, some portions of which 
 remain still attached to the arms. The extent and outline of 
 the membrane are very distinctly preserved. Some of the 
 arms are broken off at the termination of this membrane or 
 disk, while others extend to some distance beyond its limits ; 
 all however are imperfect. 
 
 The appearance of serratures is due to exfoliation, which 
 shows the impression of the inner side upon the stone. 
 
 Fig. 2. Exterior view of another individual, in which some 
 portions of the membrane still remain, the branches being all 
 broken off just beyond the last bifurcation. 
 
 Fig. 3. The inner side showing the commencement of the 
 <;ells, which appear in some places to be in a double 
 series. The connecting membrane of the branches is removed 
 in this specimen. 
 
 Fig. 4. Enlarged view of the exterior surface of the centfEl 
 portion of an individual. 
 
 Fig. 5. Enlarged view of the inner surface, exhibiting the 
 appearance of a double series of cells, separated by a 
 depressed line in the substance of the branch. In some 
 instances these appear to be absolutely separate, while in 
 others they are connected, showing that there is but a single 
 series, and the apparent separation is due to the depression 
 along the centre. 
 
 Fig. 6. An enlarged view of a fragmert of a branch, show- 
 ing serratures on one side, with a corresponding row of 
 obscure, elevated ridges, which may perhaps be due to the 
 foldings of the branch. 
 
 Plate il. Fig. 1. An individual preserving the connecting 
 membrane almost entire, showing the sinuous outline. 
 
 Fig. 2. A specimen exhibiting the half of an individual, in 
 which the disk is unequally extended between the rays. 
 The margins are apparently entire between all of these, and 
 from whatever cause or injury this inequality maybe due, tt 
 existed in the animal while living. 
 
 i 
 
11 
 
 Fig. 3. A fragment of slate preserving portions of three 
 individuals. The connecting membrane had been removed by 
 maceration before they were imbedded in the stony matter, but 
 the branches are preserved to the length of more than seven 
 inches. It does not appear that the portions preserved present 
 the entire skeleton ; on the other hand, it is almost certain from 
 the condition of thespecimens, that the branches were originally 
 much longer. It will be observed that the branches do not all 
 show the serrated margin at equal distances from the centre, 
 but this is due to the accidental position assumed by the 
 branches as they were imbedded ; some present the exterior 
 surface for a considerable distance, and gradually turning, 
 become flattened laterally. 
 
 Fig. 4. The exterior of the base of a specimen, showing 
 the small node or radicle which proceeds from the centre of 
 the vinculum or connecting stipe. 
 
 The preceding illustrations are of a single species in different 
 degrees of preservation. The manner of branching, although 
 subject to slight modifications, is still always reliable for the 
 purposes of distinguishing the species. 
 
 Locality and Formation. — These specimens were obtained at 
 Point Ldvy, opposite to Quebec, in a band of bituminous 
 shale, separating beds of grey limestone. These strata belong 
 to the Lower Silurian series, and are of that part of the Hud- 
 son River Group which is sometimes designated as Eaton's sparry 
 limestone, being near the summit of the group ; they form also 
 the rocks of Quebec. 
 
 Collectors. — J. Richardson, Sir W. E. Logan, and James Hall. 
 
 ijrRAPTOLITHUS ABNORMIS. 
 Plate III. Fig. 1. 
 
 Description. — This species, of which only imperfect specimens 
 have been seen, presents four principal branches diver'5,mg from 
 the centre, two from each extremity of the vincuij.rii, and each 
 one of these bifurcating and branching unequally, and at une- 
 qual distances from the centre. 
 
IS 
 
 The forms above described do not by any means exhaust the 
 variety presented in this collection. With a single exception 
 however, all the specimens which offer any new light in regard 
 to the habit of the Graptolites, indicate that the mode of 
 growth was in the manner described, in branches radiating 
 from a centre, or in tufts joining in a central connecting sub- 
 stance. 
 
 The specimens from the Canadian locality afford further 
 evidence in confirmation of what we have elsewhere observed, 
 that with few exceptions, the species have a limited geogra- 
 phical range. This locality has already, after very cursory 
 examination, afforded eight new species of Graptolites, with 
 one or two species which appear to be identical with those 
 previously found in the State of New York. A compari- 
 son of specimens from more southern localities with those 
 of New York, shows a large proportion of new species ; and 
 it now appears probable that the number of American spe- 
 cies of GraptoLithus previously known (about twenty,) will 
 soon be increased by an equal number of new ones. 
 
 Locality aiid Formalioji. — Point L6vy ; Hudson River Group. 
 
 Collectors. — J. Richardson, Sir W. E. Logan, and James Hall. 
 
 i 
 
 Since the dat(! of the above communication, great numbers ot] 
 Graptolites have been added to the Canada collection : and 
 with an increased number of species, our knowledge of the 
 structure of thes.:" animals has been very much extended. Had 
 we at that time possessed all the materials which we now 
 have, the subject might perhaps have been treated in a more 
 natural order by presenting in the first place the more simple 
 forms ; but since the first two plates of the species were then 
 engraved, I follow this note with the descriptions of others of 
 the same character, which have been prepared since that time. 
 
13 
 
 (^UAPTOLITHUS FLEXILIS. 
 
 Plati III. Fig. 2-6. 
 
 Description. — Multibrachiate, bi-lateral ; branches slender, 
 flexile, bifurcating at irregular intervals ; bifurcations of conti- 
 guous branches often opposite, repeated four times within one 
 and a-half inches of the centre,havingfrom thirty-two to forty or 
 more branchlets at the extremities. Substance of branches thin, 
 extremely compressed ; non-celluliferous side smooth or faintly 
 striated ; celluliferous side with slight transverse indentations 
 when compressed vertically, and with serratures when com- 
 pressed laterally ; serratures not deep, acute at the extremities, 
 variable in prominence according to the position of the branch ; 
 about twenty-four in an inch. Branches oftijn compressed in 
 the direction of the cell to such a degree as to give an apparent 
 double serrature, orserratnre on each side of the axis. In this 
 condition the edges of the cells are at right angles to the axis, 
 very shallow, and not pointed. 
 
 When the celluliferous side, compressed in the direction ot 
 the cell, is uppermost on the surface of the shale, a line may 
 be traced across the branch joining the edge of the serratures, 
 thus showing that the two apparent serratures are but the 
 single one, S(» <'oinpresst'<l that its extremities project beyond 
 the margin. 
 
 We have thus all gradations : the smooth surface of th« 
 branch with minute striations upon the outer side; the inner 
 side when not compressed, with serratures showing a • indented 
 lines across the surface, i ■ i i r t i ; the double serration, 
 produced by more pressure in the same direction, d'CC]-CO-3ij ; 
 and again, as the branch is turned around, these serratures dis- 
 appearing from one side, and becoming more prominent upon 
 the other • ::l-: : ;,.j...,j..^j,^ , finally showing their full breadth as the 
 ray is compfessed in its transverse or lateral direction. 
 
 This condition, which has not been understood with regard 
 to many species, is the principal cause of the diminution and 
 sometimes final disappearance of cells towards the base of a 
 branch. When both sides are serrated, a less degree of 
 
14 
 
 compression, which might very naturally result towards the 
 base, would cause the serratures to be less prominent, as is 
 seen in many of the figures in Barrande's Graptolkes de 
 Bohime; in the New York Palaeontology, etc. It is still true 
 that the serratures are always less developed towards the base 
 of the frond. 
 
 The serratures of this species differ essentially from those of 
 any other in the Canadian collection, and from any in the 
 New York collections or others that have come under my 
 observation. 
 
 Fig. 2. A part of an individual showing the central con- 
 necting stipe or vinculum from the radicle, two of the main 
 branches on one side and one on the other, with some of the 
 branches disconnected by the breaking of the slate in virhich 
 the fossil is imbedded. The celluliferous margins of the 
 branches towards the base are imbedded in the slate, and it is 
 only as they recede from the centre that the serratures become 
 gradually visible, until finally some of them are exhibited of 
 their full width as the branchlets become turned fully upon 
 one side and laterally compressed. 
 
 Fig. 3. A fragment of elate preserving parts of three in- 
 dividuals, all presenting the non-celluliferous side upwards^ 
 some of the outer branchlets being turned so as to show the 
 serratures. 
 
 Fig. 4. Enlarged view of a part of one of the branches and 
 its branchlets, showing in some parts shallow serratures upon 
 both sides of the branch from compression, as before explain- 
 ed. These sometimes appear almost equally upon the two 
 sides, and in other parts are l>arely visible on one side ; while 
 one of the branchlets is so turned as to show near its extrem- 
 ity the full depth of the serratures. 
 
 Fig. 5. View of a portion still farther magnilied, showing 
 the branchlets where the serratures are vertically compressed. 
 
 Fig. 6. Enlarged view of a fragment which is compressed 
 laterally. 
 
 Locality and Formation. — Point Levy ; Hudsoa River Group. 
 
 Collectors. — J. Richardson and E. Billings. 
 
15 
 
 GrAPTOLITHUS RIGIDU8. 
 
 
 Platb IV. Fig. 1-3. 
 
 Description. — MultibrachiatC; bi-lateral; branches blender, 
 eylindroid exteriorly, rigid, maintaining their width to the third 
 bifurcation, and beyond this very gradually diminishing ; bifur- 
 cations five in the space of one and a-half inches ; internodes 
 unequal, shorter near the base, and increasing towards the ex- 
 tremities ; serratures undetermined. 
 
 In some specimens the branches are broader and flattened 
 near the base, and the connecting bar or vinculum is broad 
 and strong, with a small central node, the base of the radicle. 
 Some portions of the corneous membrane or disk are preserved 
 in a single specimen. 
 
 The subdivisions of each branch are from fifteen to twenty, 
 or perhaps more numerous when entire ; giving from sixty to 
 eighty or more branchlets at the extremit.«^s of the frond. 
 
 A distinguishing feature of the species is its rigid and diver- 
 gent bifurcation, and the almost uniform size of the branchlets. 
 
 All the specimens of this species examined are in a coarse 
 arenaceous shale, and present the exterior or non-celluliferous 
 side only. A single specimen has the extremities of the 
 branches partially turned on one side, and gives some obscure 
 indication of serratures. Individuals are extremely numerous 
 in certain layers, and are spread out in profusion upon the 
 surfaces of the slate, the bifurcating and interlocking branch- 
 lets presenting a net-\7ork in which it is extremely difficult to 
 trace the ramifications of each individual. This character is 
 partially represented in fig. 1, pi, 4, in which the parts of the 
 individuals, other than the principal one, are represented in a 
 more subdued tone than they really exhibit in the specimen, 
 where all are equally prominent. 
 
 Fig. 1. A portion of the surface of a slab of slate, in which 
 a single individual is preserved nearly entire, with parts of 
 several others shown in the figure. 
 
 Fig. 2. A portion of a branch of a larger individual show- 
 ing the branchlets from above the second bifurcation. 
 
IG 
 
 Fig. 3. A fragment of slate showing the extremities of some 
 branchlets partially turned on one side, and having obscure 
 serrations. 
 
 Locality and Forinuf ion.— ?oh)t L^-vy; Hudson River Group. 
 
 CoUectort. — J. Richardson and E. Billings. 
 
 GUAITOI.ITIIUS OCTOBKACHIATUS. 
 pLATi V. Fig. 1-6, and Platb VI. Fig. 1-3. 
 
 Descrij>ti(m.-Frond composed ofcight simple undivided branch- 
 es, arranged bi-laterally, and proceeding from the two extremi- 
 ties of K short strong vinculum, which is subdivided, and each 
 part again divided near the base, giving origin at each extre- 
 mity to four equal rays or branchlets. Branchlets strong, 
 linear, not sensibly diminishing in size as they recede from the 
 centre, siibangular, flattened upon the outer side, with & de- 
 pressed line along the centre; obliquely striated; serrature* 
 short and strong, twenty in an inch, varying in depth according 
 to the position of the branch ; in one or two instances showing 
 a deeper inde? nation. 
 
 This specieej presents the essenfiial characteristic of eight 
 simple arms or branchlets, which appear to have been sab- 
 quadrangular in its living state, and when compressed laterally 
 are scarcely broader, excepting the sarratures, than when 
 vertically compressed. 
 
 The branches are formed by the division of the vinculum 
 at each extremity, first into two parts, making four ; each of 
 these is again subdivided almost immediately, and often so close 
 as to present an appearance as if the four branchlets on each side 
 originated from the same point. A careful examination how- 
 ever will show a little intervening space, and in one individual 
 in its young state this feature is very characteristic. 
 
 The disk is a thick carbonaceous film, much stronger and 
 eoarser than in any of the preceding species, and corresponding 
 in this respect to the stronger branches. It is moreover variable 
 in form and extent in difterent specimens, and does not always 
 appear lo be in proportion to the size of the branches. 
 
17 
 
 All the specimens yet examined present the exterior surface, 
 so that the celluliferous face of the arms has not been seen. 
 An impression of a short fragment of that surface of one of 
 the branchlets shows strong, deep indentations. The vigor- 
 ous aspect of this species contrasts with all others in this 
 collection. In one specimen, where the frond is imper- 
 i'ect, one of the arms extends to a distano*} of more than 
 eight anJ a half inches from the centre, while two others are 
 more than six inches each, and these are all broken at their 
 extremities. 
 
 In its long lineai' branches, this species resembles the G. 
 Sagittarius (Hall, Pal. N. Y., vol. I., pi. 74, fig. 1, perhaps not 
 the European species of that name), but the branches are 
 stronger and the serrations coarser ; it is moreover associated 
 with a group of species, all or nearly all of which are quite 
 distinct from those of New York with which the G. saaittarivs 
 occurs. 
 
 Plate V. Fig. J. A part of an individual of this species 
 t^howing the exterior side with the disk partially preserved, 
 with parts of the eight branchlets, which are seen to be grad- 
 ually turned to one side as they recede from the ccntie, and are 
 compressed laterally, showing the serratures. 
 
 Fig. 2. A fragment preserving a part of the disk very per- 
 perfect and much extended. The exterior only of the branches 
 is shown upon the stone. 
 
 Fig. 3. Enlarged view of a portion of the exterior of a 
 branch, showing the obliquely striated surface. 
 
 Fig. 4. A similar fragment of a branch which is turned to 
 one side far enough to show an undulating margin caused by 
 the serratures. 
 
 Fig. 5. A fragment exposing the serratures partially. 
 
 Fig. 6. A fragment showing the serratures as seen when 
 the branch is compressed laterally. 
 
 Plate VI. Fig. 1. An individual retaining a part of the 
 disk, and the outline and impression of the remainder, with 
 the eight branches, some of which are broken off near the 
 centre and others variously bent and folded, while two of 
 
 B 
 
 I 
 
18 
 
 them retain a length of more than six inches, and one a length 
 of eight and a-half inches. , , • ^ 
 
 Fig 2. A smaller individual retaining the branches m part, 
 and showing the lateral and exterior surfaces, vviih an irregu- 
 
 %\1 3. A small specimen preserving the base of the 
 branches with the disk removed. This one show^ more clear- 
 ly than any other specimen the bifurcation of the bianche. 
 
 beyond the vinculum. 
 
 Locality and Fomatlan.-Vomt L(5vy ; Hudson R.ver (.roup. 
 Collectors.— Z. Richardson, and E. Bilhnge. 
 
 
 Graptolitiius octonauius. 
 
 Bescrivtm .-Frond composed of four principal branches, two 
 diverging from each extremity of the short vinculum ; each 
 branch equally subdivided near the base, giving eight branch- 
 lets which continue simple to their extremities ; branchlets 
 gradually expanding from the base ; serratures slightly mclmed 
 and truncated above almost rectangularly to the direction of 
 the outer margins and oblique to the rachis, giving a slightly 
 obtuse extremity ; about twenty-four in the space oi m inch ; 
 Bubstance of the branchlets thick ; divisions between the cells 
 marked by a strongly depressed line which exten.ls horn the 
 base of the serrature downwards as far as the .eeond serrature 
 below, ending near the back or lower side oi the bnmch 
 
 The branchlets of this species resemble those ot Gr. bnjon- 
 oides, and the distance of the serratures is almost the same, 
 while in some well preserved specimens the obliquity of these 
 Darts is greater. There is also some difference m the form ot 
 the branchlets. In separate branches the characters are too 
 aearly alike to offer the means of discrimination, unless they are 
 in a very perfect state of preservation. 
 
 From G. octobrachiatvs it differs conspicuously in the lorni 
 of its branchlets, and in the comparative number and form ot 
 
 the serratures. 
 
 Localky and Formation.-Vomt L " •- Hudson River Group. 
 
 Collectors.— 3. Richardson, E. Billi , , 
 
 ^M 
 
19 
 
 OhAPTOLITFIUS tiUAI>RlHRACHIATU8. 
 Pi,ATB VII. Fig. 1-B. 
 
 Description. — Frond composeil of four simple undivided bran- 
 ches arranged bi-latorally, or two from eacli extremity of the 
 vinculum; branches slender, linear, obliquely striated, usually 
 somewhat incurved, serrated upon the inner side ; serratures a 
 little recurved, and mucronate at the tip ; about twenty-four 
 in an inch, indented to about one-third the width of the branch 
 when completely flattened. Disk thick, strong, often exten- 
 ding along the branches and giving them a somewhat alate 
 appearance; point of attachment of radicle obscure. 
 
 Almost all the specimens of this species are obscure, and 
 ali are fragmcMitary ; in a few specimens only the serratures 
 are exhibited with some degree of perfection. The branches 
 are preserved in some specimens to an extent of two inches. 
 
 Figs. I and 2. Fragments of this species from which the disk 
 has been entirely removed, but preserving the vinculum and 
 bases of the branches, which show the serrations partially. 
 
 Fig. 3. An individual in which two of the branches are 
 well preserved, showing the serratures. 
 
 Fig. 4. An enlarged view of a portion of a branch showing 
 the form of the serratures. 
 
 Fig. 5. A fragment preserving the disk, which has the 
 branches broken off just beyond its margin. 
 
 Locality and formation — Point L^vy ; Hudson River Group. 
 
 Collectors. — J. Richardson, E. Billings, Sir W. E. Logan, 
 James Hall. 
 
 Graptolithus crucifer. 
 
 Description. — Frond composed of four simple strong branches 
 united by a small thickened disk ; branches broad, connected 
 by a short vinculum ; serratures nearly vertical to the direction 
 of the branch and slopirg at an almost equal angle on each 
 side, acute at the extremity and apparently mucronate or 
 setiferous ; about twenty-four in an inch. 
 
 I 
 
20 
 
 This »i"'ci<« «hil.it» Ihe g-Mwral rimractcr of G. quadn- 
 IracMi,.,,., but the brauches are much 't^'*"' "'"' ,f ""^ 
 twice, tlu. wi,lth. Th. s<Tn>tureB arc scarcely obhquc to the 
 X la arc very Ceariy nu.crouate .t the tip. » -o^. 
 of then, i.rescut the appearauc.. ol long setie. The unpertcc 
 l»c vatiou of the speciu.cu e.vau.ined rcuders .t uuposs.ble 
 to dcfrmine ac.-uratcly the nature of these appeudngcs. 
 
 I, the specimen here aescribcl one of tie branches « pre- 
 semM to he extent of two and a-half inches, w.th a w.dth 
 tl r«-ixtecnths of an inch to the cxtrennty of the po.nts 
 fhe lerrailtres, cxch.sive cf the set..e, the branch to the base ot 
 the teetll bcinir five-sixllis of the whole width. 
 
 M;,., „„;f„,™,.,:o«.-Poiut L<ivy , Hudson R.ver Group. 
 CoUfMis.—}. Richardson, E, Bilhngs. 
 
 (iBivroi.mil s mtvosoiDKs. 
 
 D«r;,«;»».-Fro«d composed of four short simple branches, 
 uuUed a the base by a vinculum, and terminating below in a 
 minute radicle , branches short, comparatively broa.1, obl.qudy 
 and strongly striated from the base of the serraturcs to the 
 ^uter Xe of branch ; serratures moderately oblique, the outer 
 a^dn.e°r margins making very nearly a rigl.; angle; mucro- 
 r.to a the tip ; from tv.enty-four to twenty-eight m an inch. 
 Oftvml spcci-nens in the collection none of the branches 
 exceed 1 1 incl! in length, while they arc almost one^.ghth 
 „ a, inch in widt', from the tip of the solid part of the serra- 
 t„re to the outer ed,e. They are all strongly striated from 
 the base of tlu. s.-iatures t„ the outer margin the stria- 
 omethl a little cui^ved. The serratures are usually slight y 
 Xe, or with the longer sloping side directed to.-ards are 
 base of the branch, and the shorter side advanced a e be 
 yond a right angle to the rachis. In one specimen where ti 
 inches are liSs than five-eighths of an inch in length he 
 serratures seem to be equally or nearly equally slopmg on the 
 
 two sides from the tip to the base. u„jji„„ 
 
 The vinculum is obscure i and from the mode ot imbedding, 
 
 in many specimens, this part might be inferred to be aoscnt 
 
91 
 
 rjuadri- 
 about 
 to the 
 somt* 
 perfect 
 )0S8ibU? 
 
 is pre- 
 i^idth of 
 oints of 
 ' base ot 
 
 Group. 
 
 rauches, 
 low in a 
 bliquely 
 js to the 
 the outer 
 ; mucro- 
 
 an inch, 
 branches 
 ne-eightli 
 the serra- 
 ited from 
 the stria* 
 y slightly 
 wards the 
 
 little be- 
 where the 
 mgth, the 
 ing on the 
 
 mbedding, 
 G absent 
 
 LoaiJiiy and Formation. — Point Ldvy ; Hudson River Group. 
 Collectors -'J . Richardson, E. Billings, Sir W. E. Logan, 
 •fames Hall. 
 
 GRArTOLITlILS IIliADl. 
 
 Description. — Frond robust, four-branched ; disk hngo, 
 sub-quadrangular, moderately extenf^ed along the brunches ; 
 branches strong, much olonguted, sub-angular exteriorly ; ser 
 ratures siDall, acute, from twenty-two to twenty-four in on 
 inch ; fine distinctly marked strict' extend from the bas<» of 
 the serratures nearly across the branch. 
 
 The specimen described presents the disk, which in its dia- 
 meter across the centre between the branches is nearly "no inch 
 and an eighth, or nine-sixteenths of an inch on each side of the 
 centre ; while from the centre to its extent along the branches 
 it varies from about three-fourths of an inch in one branch to an 
 inch in another. The substance of the disk is strona and 
 somewhat rugose, either from its orginal character or from 
 the accidents accompanying its imbedding in the rock. The 
 specimen exhibits the inner or serrated side, ajid the branches 
 are turned so as to be compressed laterally at a distance of 
 two inches or more from the centre ; one of the branches 
 presents a length of nearly seven inches from the centre. 
 This species is named after its discoverer, Mr. John Head. 
 
 Locality and Formation. — Point Ldvy ; Hudson River Group. 
 
 Collectors.— ^Ir. John Head, and Sir W. E. Logan. 
 
 Graptolithus alatus. 
 
 Description. — Frond composed of four branches; diskniiicji 
 extended along the sides of the branches, giving them an 
 extremely alate character; branches strong, angular on the 
 lower sidcj upper or serrated side unknown. Some inden- 
 tations on the exterior side of the branches, which may indicate 
 the place of serratures on the opposite side are about one 
 twenty-fourth of an inch distant. 
 
 The only specimen of this species yet recognised is a part 
 of the disk with three of the branches, two of which pre- 
 
22 
 
 sent the corneous expansion apparently antire, extending 
 about two inches from the centre along the branches, while its 
 margin in the indentation between the branches is not more 
 than three-eighths of an inch from the centre. This species is 
 much more robust than G. qnudribrachiatus or G. hryonoidcs, 
 and the form of the disk when preserved will always be a dis- 
 tinguishing feature. 
 
 Locality and Formation.-Tomt Ldvy ; Hudson River Group. 
 
 Collectors.— Mr. John Head, and Sir W. E. Logan. 
 
 Graptulitiius fkuticosus. 
 
 Desrnption.-BrancheH bifurcating from a long slender fili- 
 form radicle, and each division again bifurcating at a short 
 distance above the first ; branclu^s and branchlets short, narrow 
 linear; serratures apparently commencing in the lower axil, 
 where there are one or two between the first and second bilurca- 
 tions. Serratures somewhat obtuse at the tip ; lower side longer, 
 upner margin nearly at right angles to the rachis ; about sixteen 
 serratures in the space of an inch. Substance of the branches 
 
 thin, fragile. , 
 
 In one spocimen the position of the serratures is such as to 
 present elongate acute apices in one of the branches. 
 
 This species has the general habit of G. nitulus and G. bryo- 
 mides, but is very distinct in it., long, slender radicle, narrow 
 fragile branches, and distant, obtuse serrations. Two indivi- 
 duals only have been obtained, but tl o form and habit are sc 
 precisely alike, and so distinctive in both of these, as to mark 
 it a verv well characterised species. 
 
 LocalW/ and Formation. -Ulund of Orleans ; Hudson River 
 
 (xroup. 
 
 Collectors.— J. Richardson, E. IVUings. 
 
 GRAVTOLITlirS INDKNTUS. 
 
 Dcsn'iptton.— Frond consisting of two simple branches, di- 
 verging at the base frotn a slender radicle, and continuing 
 abo\'e h. a nearly pamllel direction ; branches narrow, slender ; 
 
 t 
 
serratures very obliriue, somewhat obtuse, truncated above 
 almost rectangularly to the line of the rachis ; about twenty- 
 lour in the space of an inch ; a depressed line reaching from 
 the serrature to near the base or outer margin of the branch 
 where it terminates in a small node ; surface of branches striate. 
 
 This species resembles the G. vhuhs in fonn, except that it 
 is less divergent, the divergence from the base being at an angle 
 of about thirty-six degrees for half an inch or more, after which 
 the twobranches continue nearly parallel. Though it is probable 
 that this character may vary in some degree, it seems never- 
 theless to mark the species, and in numerous individuals of 
 G. nitldm I have seen none with parallel or converging branch- 
 es. The serratures in the two species diifer in some degree 
 in form, and the proportional distances, thirtj^-two and twenty- 
 four, form a very characteristic distinction. A single fragment 
 of a branch measures six '''ches, but the full extent when 
 perfect is not known. 
 
 Locality and Formation. — Point Levy ; Hudson River Group. 
 
 Collectors. — Sir W. E. Logan, James Ilall. 
 
 t 
 
 GRAPT(nJTHrS NITIDUS. 
 
 Description. — Frond composed of two simple brai ches, diverg- 
 ing from a small radicle ; branches narrower towards the base, 
 gradually expanding towards the extremities, which in perfect 
 specimens appear to be rounded, and the last serrations a little 
 shortened ; serratures small, shorter at the base and becoming 
 gradually developed as they recede from this point ; acute at 
 the extremities, almost vertical to the line of the rachis, and 
 making an angle of about sixty degrees, the two sides being 
 almost equal m length ; about thirty-two in the space of an inch. 
 A well-defined jrroove or depressed line extends from the base 
 of the serrature obliquely towards the base of the branch, and 
 at its termination the surface of the branch is marked by 
 minute but distinct round tubercle. 
 
 This beautiful little species differs very distinctly from any 
 others of this genus, in the thickened substance of its branch- 
 es, the closely arranged serratures, and the minute tubercles 
 
 I 
 
24 
 
 at the base of the grooves or strif«. The specimens nsually 
 preserve considerable substance, and are far less flattened than 
 most of the other ^)ecies, owing either to their original cha- 
 racter or to the nature of the surrounding matrix. The im- 
 pressions of the oblique lines or stria^ are often well preserved 
 in imprints of the fossil left in the slate. 
 
 The impressions of G. bnjonovkfi resemble those of this 
 species ; but the branches are broader, and the strife are less 
 rigid and less distinctly impressed, while the absence of 
 tiibercles, and the coarser serratures, when visible, at once 
 serve to distinguish the species. 
 
 In mode of growth and general aspect this species resembles 
 the G. scrratulus (Pal. N. Y., vol. I, p. 274, pi. 74, fig. 5, a, b,) 
 of the Hudson River shales; but in the latter the serratures 
 are coarser and more oblique, the lower side being much the 
 longer. The branches of that species are also more distinctly 
 linear, while in this they become gradually wider from the 
 base, and are very distinctly striate and tuberculate in well- 
 preserved specimens. 
 
 The preceding description applies to the specimens of this 
 species where the branches diverge abruptly, or nearly at a 
 right angle, from the radicle. 
 
 LocalWi and Formation.— Fomt Levy ; Hudson River Group. 
 
 Collectors.— J. Richardson, E. Billings. 
 
 Oraptolithus HIFIDrS. 
 
 I>csr;v>r/o//.— Two-branched ; branches very gradually and 
 uniformly diverging from the base to the extremities ; surfaces 
 obliquely striated ; serratures moderately oblique ; extremities 
 often nearly vertical ;o the rachis, and submucronate (?) ; 
 from thirty-eight to forty in the space of an in(;h ; radicle 
 
 short. 
 
 This species resembles in general features the G.iilfidns, and 
 might be mistaken for that species with the branches approxi- 
 mated by pressure. In several individuals examined the ser- 
 ratures are much closer, being from six to eight more in the 
 ppace of an inch, while the general form is constant. The 
 
I 
 
 < 
 
 outer margins of the branches are curved for a short distance 
 from the radicle, and thence proceed in a unifonn divergent 
 line. The entire branch is very narrow at the base, but becomes 
 gradually wider, the full width being attained at about half 
 an inch from the bifurcation, while a few of the serratures to- 
 wards the outer extremity, not having attained their full de- 
 velopment, leave the brandies narrower in that part. The 
 same feature is observed in G. nitidus and others of this gene- 
 ral character, and probably may be observed in all species 
 where the extremities of the branches are entire. 
 
 Locality and Formation. — Point L^'vy; Hudson River Group. 
 
 Collectors. — J. Richardson, E. Billings. 
 
 GRArTOLITIIUS PATULUS. 
 
 DcscrijHion. — Frond composed of two simple widely diverg- 
 ing branches from a small radicle ; branches long-linear, hav- 
 ing a width from the base of the serratures to the back of the 
 branch of from one-sixteenth to one-twelfth of an inch ; serratu- 
 res oblique, with vertical mucronate points, which from base to 
 apex are more than half as wide as the branch. A well detined 
 line or ridge extends downwards from the apex of the denticle 
 two-thirds across the branch. 
 
 Fragments of this species are numerous upon some slabs of 
 greenish or blackish-green slate where no otiier species occurs. 
 The fragments are sometimes five or six inches in length, offer- 
 ing in different individuals little variation in width. Some- 
 times the branches are compressed vertically, and present the 
 smooth linear base or exterior, wliich is less in width than 
 when compressed laterally. 
 
 The lateral faces of the branches exhibit considerable vari- 
 ety of surface, dependant on the degree of compresf ion, or 
 in some instances, the replacement or filling of the interior by 
 iron pyrites. In such cas«'s, or when the branch is not flatten- 
 ed, the surface is deeply striated or wrinkled obliquely. In 
 some of the extremely compressed individuals the surface has 
 an appearance of vesicular structure ; but this is probably 
 due to influences attending the mineralization of the fossil, or 
 
26 
 
 the filling up of the original canal, and not to the structure of 
 the substance itself. 
 
 Locality a?id Formation.— FomtL6\y ; Hudson River Group. 
 
 Collectors. — J. Richardson, E. liilliiigs. 
 
 Graptolitiius extensus. 
 
 Description. — Frond probably two-branched ; branches long- 
 linear, varying in width in different individuals from one-twelfth 
 to one-tenth of an inch exclusive of the serratures, and from 
 one-tenth to one-eighth of an inch including the serrature:,. Ser- 
 ratures oblique, with the extremities slender and nearly erect, 
 mucronato at the tip ; about twenty in the space of an inch ; 
 base of branch scarcely narrowed, showing a few smaller ser- 
 ratures ; surface strongly striated, the striae being preserved 
 in those specimens which are extremely compressed. 
 
 The branches of this species bear a very close resemblance 
 to those of G. octobrachiatm, but an individual in which the 
 h^ae is preserved shows in its peculiar curving and smaller 
 serratures a feature which belongs only to the two-branched 
 forms. The serratures also appear to be more slender, and are 
 slightly closer in their arrangement ; branches of the same size 
 in the two, presenting respectively eighteen and twenty ser- 
 ratures. 
 
 This species in separate branches of from three to six or eight 
 inches in length, is abundant on some slabs of decomposing 
 grayish-brown shale, associated with G. bryonoides, G. nitidus, 
 and others. 
 
 Locality and Formation. — Point L(3vy ; Hudson River Group. 
 
 Collectors.— i. Richardson, E. Billings, Sir W. E. Logan, 
 James Hall. 
 
 Graptolitiius denticui.atus. 
 
 Description. — Frond apparently consisting of two broad 
 branches, (the base and junction of which are obscure in the 
 specimen ;) margins defined by a rigid line, beyond which on 
 the inner side, are serratures having the funn and charac- 
 
 
27 
 
 ter of small denticulations inserted upon the margin of the 
 branch and vertical to its direction, broad at base, abruptly 
 tapering above, and ending in mucronate points ; about sixteen 
 in the space of an inch. 
 
 This very peculiar species is readily recognised by the den- 
 ticulations, which have the character of small sharp teeth 
 fixed upon the margin of the branch. These denticles are 
 more vv^idely separated than those of any other species ob- 
 served, as well as difterent in character. 
 
 Locality and Formation. — Point Ldvy ; Hudson River Group. 
 
 Collectors. — Sir W. E. Logan, James Hall. 
 
 Graptolitiius pristiniformis. 
 
 Description. — Stipe simple, with serratu'os on both sides ; 
 serratures closely arranged, very oblique, acute, mucronate ; 
 thirty-two in the space of an inch. 
 
 This species approaches to G.-pristis (Pal'^.Y., vol I., p. 265, 
 pi. 72, fig. 1), but the seiTatures are more ascending, and the 
 extremities more distinctly mucronate. The specimens observ- 
 ed however, are imperfect fragments, which are very closely 
 compressed, being barely a film upon the surface of the shale, 
 and the determination is somewhat unsatisfactory. 
 
 Locality and Formation. — Point Ldvy ; Hudson River Group. 
 
 Collector. — J. Richardson. 
 
 Graptolitiius exsiformis. 
 
 (Genus Retiolites? Barrandc.) 
 
 Description. — Stipe simple, sub-eusiform or elongate-spatu- 
 late, usually broader in the middle and narrower towards the 
 extremities; a central rib, with strongly marked obliquely 
 ascending stria) which reach the margins ; serratures obscure, 
 apparently corresponding to the striae; margin usually well 
 defined. 
 
 Several specimens of this form occur on a single slab of 
 slate, associated with U. tcntaculatiis and G. <juadribrachiattts. 
 
 I 
 
2« 
 
 The oblique strife apparently indicate tlie direction of the ser- 
 ratures, and in one specimen tlioro is an appearance of obtuse 
 indentations upon the margin ; but it is scarcely possible at 
 the present time to define srlisuictorily the character of these 
 serratures. In form and general character this species differs 
 from all the others sufficiently to be readily distinguished. 
 
 Locality and Formation.— ^oint Levy', Hudson River Group. 
 
 Collector.^.— :i. Richardson, Sir W. E. Logan, James Hall. 
 
 Gkaptolitiius tentaculatus. 
 
 (^Gcnus Retiomtes, Barrande.) 
 
 DescriiUion.—Ht\ve simple, linear, elongate-lanceolate or 
 sometimes elongate-elliptical when entire; midrib double, ex- 
 tending much beyond the apex of the frond ; exterior margins 
 when entire, reticulate and armed with mucronate points, (and 
 withmucronate points alone, or smooth, when imperfect,) with 
 an extended setiform tentacle-like process from each side of the 
 basal extremity ; substance of the centre reticulate or cel- 
 
 ^"^^^^ . ^ A , 
 
 This species presents much variety ol appearance dependant 
 
 upon the condition of preservation. In specimens most nearly 
 entire, the double midrib often extends beyond the apex 
 nearly as far as the length of the frond ; the margins present 
 a series of oval or sub-hexagonal reticulations, every second 
 one (and sometimes each one,) of which is armed by a minute 
 mucronate spinule. When these outer cells or reticulations 
 are broken away, the transverse walls between them often 
 remain, and the specimens then present an undulating margin, 
 with a short mucronate extension, which is the original wall 
 between the marginal reticulations, and which is continuous 
 with the strife or fibres which traverse the frond from the 
 niidrib to the margins. On each side of the basal extremity 
 the long setiform fibres extend obliquely forward to the dis- 
 tance of half an inch, and between these are two short ter- 
 minal ones, like the processes on the sides of the frond. 
 
29 
 
 In inauy specimuns tlie whole exterior reticulate portion is 
 removed, leaving the frond with straight or nearly straight 
 parallel sides, the long extended midrib above, and the two 
 setiforni processes from the lower extremity ; while in some 
 specimens these parts also are removed. The serrauures can- 
 not well be determined in any of the immerous individuals 
 examined, but they doubtless correspond to the vein-like 
 markings of the centre, and the reticulate marginal extension. 
 
 Some specimens indicate that the central portion may be 
 tinely reticulate, which character, with that of the exterior, 
 would be regarded as sulticient to warrant us in referring it to 
 the genus Rctioliles. 
 
 Localitij and Formation. — Point Levy ; Hudson lUver Group. 
 
 Collectors. — J. Richardson, Sir W. E. Logan, James Hall. 
 
 PHYLLOaUAPTUS. 
 
 Among the various forms in this Canadiun (tullection of 
 GraplolitidetB there are several which ai)proach in general 
 form to (r. ovutus of Barrande, and G. folium of Hisinger. 
 They [jresent however some differences of character, varying 
 from broad-oval with the extremities nearly equal, to elongate 
 oval or ovate, the apex usually the narrower, but in a few 
 instances the base is narrower than the apex. These forms are 
 sometimes extremely numerous in the shales, and present on a 
 cursory examination a general similarity to the leaves of largt; 
 species of Neiiropteris in the shales of the coal mcasur«?s. 
 
 Instead of the narrow filiform mid-rib represented in the 
 figures and descriptions of the authors mentioned, these spe- 
 cimens present a broad linear mid-rib continued from the apex 
 to the base, and extended beyond the base in a slender filiform 
 radicle, usually of no great extent, but in some instances 
 nearly half an inch in length. The mid-rib is rarely smooth, 
 varying in width, with ity margins not often strictly defined. 
 In examining a great number of individuals of one species, I 
 have discovered that this mid-jib is serrated ; and though for 
 the most part the serratures are obscure, they nevertheless 
 present all the characteristics wjiich they exhibit in grap- 
 
30 
 
 tolites of other forms, in which the branches have been com- 
 pressed vertically to the direction of the serratures. 
 
 In this view, the lateral leaf-like portions appear to be ap- 
 pendages to the central serrated portion ; but these are never- 
 theless denticulate on their margins, and the intermediate 
 spaces are wel'-defined, as if admitting of no communication 
 bv serratures or cellular openings with the centre. 
 
 In another species the central axis or mid-rib is strong and 
 broad, often prominent an,l distinctly serrate, the edges of the 
 interspaces being all broken off as if the extremities had been 
 left in the slate cleaved from the surface. At the same time 
 the lateral portions are so well preserved as to show distinct 
 cellules upon each side. We have therefore three ranges of 
 cells visible, the central axis projecting at right angles to the 
 two lateral parts. This remarkable feature lead, to the inter- 
 ence that this graptolite was composed of four semi-elliptical 
 parts ioined at their straight sides, and projecting rectangularly 
 to each other, presenting on each of the four margins a series 
 of serratures, which penetrating towards the centre, were all 
 united in a common canal, and all sustained upon a simple 
 
 radicle. . . , 
 
 In another more elongate form, the specimens examined aie 
 extremely compressed, and I have not been able to detect ser- 
 ratures in the axis, which however is sufficiently wide to admit 
 
 of this feature. , . r , •, ^ i 
 
 For these remarkable forms, whether consisting of bilateral 
 or quadrilateral foliate expansions, or with two or four series 
 of ceUules, I propose the name of Phyllograptus, from their 
 leaf-like appearance when compressed in ^he slaty strata. 
 
 It is easy to perceive how bodies formed as these are inay 
 present different appearances, dependant upon tne line of separ- 
 ation of the parts by the slaty Uiminae. When separate-, 
 longitudinally through the centre, the cells of the parts later- 
 ally comprefsed would be seen with the mid-rib not strictly 
 defined ; and the bases of the cells of that part vertically com- 
 pressed, scarcely or not at all visible. When a small portion 
 of the base of that part which is vertically compressed is pre- 
 served, the bases of the cells remain and mark the axis. 
 
81 
 
 When instead of being imbedded so that two parallel sides are 
 compressed laterally and the other vertically, the whole frond 
 lies in an oblique position, the two adjacent rectangular parts 
 are spread open and flattened upon the surface of the slate, the 
 specimen then appears as if the cells were conjoined at their 
 bases, or as if separated by a filiform mid-rib. An individual 
 compressed in this manner and then separated through the 
 m;ddle, will present the bases of the two adjacent divisions 
 with the cells lying obliquely to the plane of the slaty laminae. 
 These and other varieties of appearance are due to the position 
 in which the fossil was imbedded, nnd the direction of the 
 cleavage or lamination of the slate. 
 
 PlIYLT.OGKAPTt'S. (NcW GeUUS.) 
 
 Description. — Frond consisting of simple, foliate expansions, 
 celluliferous or serrated upon the two opposite sides ; margins 
 with a mucronate extension from each cellule ; or of similar 
 foliate forms united rectangularly by their longitudinal axes, 
 and furnisheci on their outer margins with sinnlar cellules or 
 serratures, the whole supported on a slender radicle. 
 
 These bodies which usually appear upon the stone in the fonn 
 of simple leaf-like expaifsions, may possibly have been attached 
 in groups to some other support ; but the form of some of 
 them, and the character of the projecting radichi at the base, 
 indicates that we have the entire frond. These forms furnish 
 perhaps the best illustration of all the Grnptolitideie, of the 
 lesser development of the cells at the base, and their gradual 
 expansion above., until they reach the middle or upper part of 
 the frond Many of them diminish from the centre upwards, 
 and rarely the cells are more developed above the centre, re- 
 versing the usual form, and leaving the narrower part at the 
 base. 
 
 PlIYLLOGRAl'TlS TYPUS. 
 Platb VIII. Fio. 1-11. 
 
 Dcscriinion. — Frond elliptical, elongate-ovate or lanceolate, 
 
32 
 
 broad-oval or obovate ; luarghis ornaiiuiiited by mucronatc 
 points ; serratures clowly arrangod, about twenty-four, rarely 
 tweuty-tvvo and sonietinies twenty-six in an inch, usually 
 obscure at the margins ; axis or mid-rib broad, often crenulate 
 or serrate ; radicle usually short ; frond robust. 
 
 This species assumes considerable variety of form ; and 
 from the oxannnation of a few specimens of the extrem?s 
 of the series <jne might be disposed to regard them as 
 distinct species. After examining several hundred indivi- 
 duals however, I have not been able to find reliable cha- 
 racters in the form, or subordinate parts, to establish specific 
 diii'erences. Tlie individuals figured rejjresetit the principal 
 varieties noticed, though a greater nundjer of forms might have 
 been given. I have not thus far observed forms intermediat«^ 
 between the short broad ones and the more elongate oval ones; 
 but it is probable that larger collections will furnish such. 
 The number of serratures in entire fronds varies in different in- 
 dividuals from twenty-five or twenty-eight to fifty on each 
 side, depending on the size and form of the specimen. The 
 smallest examined have about twenty-five on each side. 
 
 The specimens of this species examined are all so much 
 compressed that the rectangular arrangement of the parts ol" 
 the fiond, as seen in P. ilicijhlim, caimot be shown, the only 
 evidence of this character being the serratures along the cen- 
 tral axis, which are transverse to those of the two sides. 
 
 Hgures 1, 2, 3, 4. Examples of the ordinary forms of this 
 species. Fig. I shows a smooth axis; while figures 2, 3 and 4 
 show indistinct serratures along the mid-rib. 
 
 Figures 5, 6, 7. Specimens whicli are more elliptical than 
 the ordinary forms ; the mid-rib or axis is well defined, but 
 preserves no evidence of serratures. 
 
 Fig. S. A bioad oval form, showing serratures along the 
 axis. 
 
 Fig. y. An obovate fonn, showing serratures along the 
 axis. 
 
 Fig. 10. A very large and elongate frond, showing more 
 than fifty serratures on each side ; the central axis shows no 
 serratures. 
 
.'J3 
 
 Fig. 11. A frai^mfnt of slute preserving twelve individuals 
 of small size, upon tiio surface. 
 
 Loca/lfif mid Formation. — Point Li^vy ; Hudson Rive Group 
 Cc^'ector. — J. Hirnnrdson. 
 
 PHYLLOrJKAl'TrS ILICIFOIJUS. 
 
 Drscriptio7i.— Frond apparently broadly oval or ovate, witk 
 the margin ornamented by mucronate points ; mid-rib or axis 
 broad, serrated ; the extension of the serratures broken off in 
 the separated liimina' of shale ; radicle short. Serratures from 
 thirty to thirty-two in the space of an inch, varying slightly 
 with the proportionate length of the frond. 
 
 The form in reality however is that of two broadly oval or 
 ovate leaves or fronds, joined rectangularly at their centres or by 
 the longitudinal axis, and in a transverse section presenting a 
 regular cruciform figin-e. The expansions of the two sides, 
 which are laterally compressed, show distinct serratures or 
 cells with projecting mucronate extensions. Those which are 
 vertically compressed have their outer portions broken off in 
 the separated laminae of slate, and present the bases of the 
 cells, which, having sometimes been filled and distended with 
 mineral matter before imbedding, are very conspicuous. In a 
 few instances the cells of the lateral portions are filled in the 
 same manner, presenting the character of curving, conioftl 
 tubes, with the l)roader extremity outwards. 
 
 The condition of preservation in several species examined is 
 such as to render unavoidable any other conclusion as to their 
 mode of growth than the one I have given above, however 
 anomalous it may seem. This species differs from F. ti/pus in 
 its thicker substance, proportionally shorter and broader form, 
 and more closely arranged serratures. 
 
 Loculitij and Formation. — Point Ldvy ; Hudson River Group. 
 
 Collector. — J. Richardson. 
 
 Phyllograptus angustifolius. 
 
 Dtstriytwn. — Frond elongate-elliptical or elongate-lanceolate, 
 
 c 
 
34 
 
 closely serrated ; Berraiurcs funuKhod with mucroimte .'xten- 
 sions, about twenty-four in the space olan inch; mid-rib broad, 
 s'.noo h; radiehs scarcely preserved. 
 
 This species is readily distinguished from either of the pre- 
 cediiisj by its narrow and elongate form. The individuals 
 examined are very numerous, but being for the most part 
 upon slaty laminas which are extremely compressed, they 
 preserve scarcely any substance ; a mere outline with a more 
 brilliant surface being abnost tlie only remaining character by 
 which they are recognized. 
 
 The individuals of this species are, in several specimens, 
 equally abundant with those of Fhyllograptus tijims represented 
 in pi. 8, fig. 11. The mucronate extensions upon the margins 
 of this species are not so abrupt as in P. ti/pns and P. iUc'iJhlhis, 
 the substance of the cell-margin being more extended along 
 the mucronation. The number of serratures upon each side of 
 the frond varies according to the size ol'the individual, being ordi- 
 narilv from eleven or twelve to twenty-four, while in a single 
 individual of nearly two inches in length there are forty-three 
 or forty-foTir on each side. The mid-rib in this species though 
 broad, like those of tl: preceding species, is not conspicuously 
 serrate in any of the specimens examined. T';is feature how 
 ever may have been obliterated by pressure. 
 
 Locfd'ty and Formatioi}. —Vomi Levy ; Hudson River Group 
 Collector. — J. Richardson. 
 
 I 
 
 PlIYLLOGRAPTUS SIM1L18. 
 
 Drsciipuon.—Vrond broad-oval ; margins ornaiiiented l)y 
 slender, sub-mucronate serratures, which are closely arranged, 
 being in uhe proportion of thirty-two to an inch, usually from 
 thirteen to sixteen upon each side; axis disjoined; radicle 
 
 unknown. 
 
 This species exhibits much variety of aspect. The more 
 perfect forms are broadly oval, the diameters being about as 
 six to seven. The central portion is open and free from any 
 organic substance, as if theio had originally been a cavity in 
 the place of the longitudinal axis. In other specimens the 
 
S6 
 
 parts ai-p 8('[)arnt«Ml at oiio nxtremity, and appear like three or 
 four branches closely joined at the other extremity, givinu; it 
 the aspect of a four-branched frond. On examining numerous 
 spi'cimens they appear to iiave been originally arrangcid like 
 the si)ecies of this genus already described, with perhaps this 
 dillerence, that th»' margins of tiu; axial portion were not close- 
 ly united, or were quite disjoined along the centre. From the 
 equal extre.Miities of the frond, and the almost rectangular 
 serratures, conjoined with the very obscure condition of the 
 8pe<'imen8, it has not been possible to determine whether the 
 se})aration of the parts at tlie extremities has taken place at 
 the base or the sunnnit. 
 
 TIJ.s species occurs associated with 6*. Logani and G. quad- 
 rifjrac/ildfus. 
 
 LocaWy and Formation.— .Vo'mt L('n'y ; Hudson River group. 
 
 Collectors. — Sir W. E. Logan and James Hall. 
 
 Besides the forms described in the preceding pages, there 
 are several others belonging to the genus r;m/W/'////,s-, of which 
 I have not specimens in sutlicient perfection to furnish a proper 
 description ; and there are others which, possessing some abnor- 
 mal characters, I hesitate to describe as distinct species, until 
 I shall have an opportunity of seeing more specimens. 
 One of these, having the general character of G. octobiadua- 
 tus, has but seven branchlets, three from one extremity of 
 the vmculum and four from the other, bifurcating as in the 
 species named above. The branches, liow^'ver, are more slen- 
 der than in G. octobruchiatus, and it may prove to be a u. ..inct 
 S23ecies. 
 
 Another form having the general habit of G. Logani has but 
 nine branchlets, four from one and five from the other side of 
 the vinculum. The exterior side only is visible, and the 
 branches being broken off a short distance from the vinculum, 
 HO opportunity is offered of examining the serratures. It seems 
 quite probable that this may prove a distinct species. 
 
 A single fragment of a ramose form, with two branches like 
 G. ramosns, of New York, has been observed, but I have not 
 thought it desirable to give its characters at present. 
 
Amoni? other forms of the GnfptoUfhlrf/:, thorc nif at h'ast 
 three species o{ D'lctyommth wliicli :ir;> o ('onimoii oi'curreuce, 
 associated with the (iraptolites of Point Lt'-vy. 
 
 The genus D/cdjoncma was Jescvibed in the Palreontoloiry 
 oi New York, vol. 2, p. 174, from iiii oxamlnatiou of the hioad 
 flabelliform or sub-circuhir expansions of conu'ons reticuhiied 
 fronds common in tiie shak'S of the N ia-s^'ani uronj). These forms 
 were described as having •' the ai)i)earance and texture of Grap- 
 tolites, to which they were douljtiess ch^sely allied," L'urther 
 examinations have demonstrated the tiiith ol tliis reuiark in tlie 
 discovery of serratures, like those of Graptolithnx, on rlie iimer 
 side of the branchk'ts of both D. n,'ifi>rmif! and J>. ^arari/is. 
 The celluliferous side adhering more ch)sely to tht; si one tiian 
 the opposite, as in Rctepora and Fcnr.snlht. isnnicii nioiv rarely 
 seen than the other, The mode or growtli, thouuh probably 
 flabelliform in some species, is clearly funnel sha[)ed in I), rct'i- 
 formis, the serratures being upon the inner side as in Foitstdla. 
 The iieneric characters heretofore given may therefore be 
 extended as follows. 
 
 1 
 
 !^ 
 
 DKJTYONKMA. 
 
 Generic characters. — Frond consistinii ol' ihibelliform or tun- 
 nel-shaped expansions, (circular from compression) coniposed 
 of slender radiating branches, which IVetpiently bifurcate as 
 they recede from the base ; branches and sulxlivisions united 
 laterally by hue transverse dissepimems; exterior of branches 
 strongly striated and often deeply indented ; inner surfacts 
 cellulilerous or serrate, as in Graptn/ifmfs-* 
 
 The general aspect of the species of this genus is like thai, 
 of Fcncstclla, both in the form of the fionds and the bifur- 
 cation of the branches. Soukj of tiie species have hereto- 
 
 • A paper by J. W. SaUer, Esq., Pitlreontologist of the Geolo<rical Survey of 
 Great Britain, read before the American Assjcialion, for the advaucenient of 
 Science, at the Montreal Meeting, 1857, describes a new genus of the Graptolito 
 family under the name of Graplopora. Athowgh having had no opportunity of 
 examining tiiis jiaper, it appear.^ to me tlmt the forms described are true Dictx- 
 oifuxi. 
 
 f 
 
37 
 
 fore been referred to tliat genus, and others to Gorgonla. They 
 may be known from cither of these genera by tlie striated and 
 serrated corneous skeleton, and absence of round cellules, 
 which latter character, with a calcareous frond, marks the Fe- 
 
 Since the essential characters of D/cfi/oncma; with figures of 
 two species, have been given long ago, and their similarity to 
 (Iraptolites pointed out, I am disposed to retain the name, and 
 to describe the Canadian species under that designation. 
 
 There are still two other types in this collection which seem 
 to iiici-it generic distinction. < )iie of tiiese consists of imperfect 
 brandling fronds, the smaller branchicLS of which are often 
 rigidly divergent from the main branch at an angle of about 
 thirtv-six degrees. In others the branchlets diverije in a simi- 
 lar manner, but are less rigid. Exterior of branches smooth, 
 interior suri'ace celluliferous. There are two or three forms of 
 this type which J }>ropose to designate as Dendkogkaptus. 
 
 Another form consists of fronds wliich are strong stipes near 
 the base, and become immerously and irregularly branched, 
 ending in a great number of liliiorm branchlets, one aide of 
 which is serrated. The gt;neral aspect is that of a shrub or tree 
 in miniature. For these forms I would propose the generic 
 name of TiiAMNOGHAPTtTS. 
 
 There is also a single species approaching in character to 
 that published in the Report of the Fourth Geological District 
 of New York as Filiciics? The lateral branchlets are much 
 longer, more lax and slender, being in this respect more nearly 
 Uke FiUcites g^radlis of Shumard, (Geol. Report of j\Iissouri, 
 part 2, p. 20S, pi. a. lig. 11) but the branchlets in the Canadian 
 species are longer and more slender. They have all the same 
 general plumose character, and from the well preserved cor- 
 neous structure in the Canadian specimens, I regard them as 
 belonging to the; Graptolitidea^ although the celluliferous or 
 serrated margins have not been seen. For these forms of Canada, 
 New York and ^Missouri, should they prove generically iden- 
 tical, I propose the name of Pli:mai.i\a, making the FUivttcs't 
 cited above, the type of the genus with the name of P/uma/ina 
 jduniaria, wiiile the western species will receive the name oi' 
 H. grndlis. 
 
38 
 
 The disk-like forms which are described in the Palaeontology 
 of New York, vol. 1, p. 277, iinier the name oi' Dhcop'njllum, 
 are probably the disks of a s[>ecies of amptolithus with 
 numerous branches. One specimen preserves a thick corneous 
 substance, wiiich is the exterior surface, while the other pre- 
 serves the mould of the opposite side, the radiating impressions 
 of which are crenulated. There are no evidences of branches 
 extending beyond the margin of the disk. 
 
 We have now so many v.ell-established forms in the family 
 GrainolUhka'., tliat we have the means of comparison with 
 other allied families among pala?ozoic fossils. 
 
 Althouuh numerous species in this collection are shown to 
 be of compound structure, or to consist of fronds composed ol 
 two or more branches, and many of them originating m, or 
 proceeding from a disk of thickened corneous substance, yet 
 it is not -improbable that there are among true Graptolites 
 simple stipes or stems, as all the species have been usually 
 heretofore reuarded. 1 am disposed to believe that those 
 Graptolites where the stipe is serrated on the two sides 
 (Dlplo'Tapsus) may have been simple from the base; and that 
 the branching forms having both sides, or one side only oi the 
 branches serrated, may possibly also have been simple, or 
 bearin- no moie than a single stipe from the radicle. Tne 
 bifurcate appearance it the base of G. bicornis however, oilers 
 some objections to this view, and these too may have been 
 comrmund, like those which have only one side serrated. 
 
 The numerous compound forms shown in this collection, 
 and the greatvariety of combination hi the mode of branching, 
 induces the belief that all those with a single se-ies of serra- 
 tures have been originally composed of two, tour, or more 
 branches, either diverging from a radicle or connected by a 
 vinculum from which the radicle has extended. 
 
 The Fh,jllo<rmptMs, although apparently an anomalous form, 
 is not more so with our present knowledge of the Graptolites 
 than G. Logam or G. octobrachiatus would have been (consi- 
 dered a few years since. 
 
 It is not among the least interesting tacts, that we should 
 find the Graplolkidea^ simulating in their mode ot growth 
 so many of tiie Palaeozoic Ihyozoa. W- h^ve Fcn..Hc//n 
 
 \ 
 
 < ■ i 
 
\ 
 
 i I it 
 
 39 
 
 repre.sented in Dictyovcma ; the ramose forms of Rctcpura in 
 Dc?uIrognq>fiis ; Glaiiconomc and IchthijoracJt'is in PlumaUva ; 
 while tlie spirally ascending forms fi^^'ired l)y I'arrande appear 
 to shnulate in their mode of growth the spiral i'orms of J'ewes- 
 tella or Archimedes. 
 
 The forms of Graptolites now known are so numerous as to 
 deserve especial consideration in their relations to other groups 
 or families of fossil or living forms. They have been referred 
 to the Radiata and to the Bryozoa. Tliey were all originally 
 composed of a thin corneous film which enclosed the bodies 
 of the animals inhabiting the cells, and formed the general 
 canal or source of communication along the axis. The sub- 
 stance of the Graptolites was then uidikc that of the Radiata 
 of the same geological age ; the sub-divisions are in twos, or 
 some multiple of two, except in a few instances which appear 
 to be abnormal developments ; and when the sub-divisions 
 are irregular there is far less similarity with Radiata. 
 
 From all Palaeozoic Bryozoa the C! i-aptolites differ essentially 
 in the form and arrangement of the cellules, and the nature of 
 the substance and structure of the skeleton ; and simulate only 
 the general forms of Bryozoan genera. 
 
 JAMES HALL. 
 
 ■