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 Un daa aymboloo auivanta apparaitra sur la 
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•as 
 
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 )LOGlCAL SURVEY OF CANADA 
 
 ROBEBT BKLIi, M.D.. 8aD. (Outeb^X I^I>., F.RS., 1.8 O. 
 
 CONTRIBUTIOIN'S 
 
 CANADIAN PAL.€ONTOLOGY 
 
 VOtJtJMR Tti (Qnarto). 
 
 fc>^/ 
 
 im^" 
 
 PART III -ON DRYPTOSAIIROS INCRASSATU^ (COPE). FROM THE 
 EDMONTON SER^ES OF THE NORTH WEST TERRITORY. 
 
 \ OCT e V53S 
 
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 OTTAWA 
 
 QOVERNMBNT TAINTING BUREAU 
 
 .'DLT, 1904 
 
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V 
 
 GEOLOGICAL SURVEY OF CANADA 
 
 ROBERT BELI M.D., f»c.D. (CnUb), LL.I»., F.B.8., I.80. 
 
 CONTHlBUTlOTsTS 
 
 CANADIAN PAL.HONTOLOGY 
 
 VOLITMK III (Quarto). 
 
 .*! €. 
 
 
 FAKT Ill.-ON I)KVm)SAl!KllS INCKASSATUS (COPE). FROM THE 
 EDMONTON SKKIES OF THE NORTH WEST TEKRITOKY. 
 
 LAWRENCE M. LAM BE, F.O.8., F.R.S.C. 
 Vertebrutf l^alaont-ilogut. 
 
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 OTTAWA 
 
 ooveknmknt printing bureau 
 
 Jilt, 1904 
 
 Nu. KTJ 
 
fi 
 
 I 
 
Th« pre«<nt inonogr«ph conttitutM lh« third pirt of volume III (qowte) of Contri- 
 bution, to ci::::di.n r.^Logy .nd U de-criptiT. of the .kuU «id c«U.n o^« P-J- 
 ofthe.keleton of the Urge crnivorou. dino..ur ^1^^;;^^^' ^T^''^^''^^^^^^ 
 \% foMil remain, now de«:ribed by Mr. Umbe were collected by oBcer. of thi. d^P*"""* 
 
 rmtr5Lonton.K.rie.ofth;Cret«=eou..y.temoftheNorth.we.tT«r^^^ 
 rprelimin.ry de« ription of the .hull, by ProfeMor Kdw.id D. Co,,e, b-ed on the Mme 
 material, wa. publbhed. in 1892, without illurtralion^ 
 
 Part 1 of thi. volume, on Vertebrate Specie, from the Oligocene or Lower Miocene 
 bed. of the Cypre» Kill., by Profewor Cope, appeared in 1891. 
 
 Part 11. on Vertebrata of the Mid-Cretaceon. (Belly River .erie.) by Profe-or 
 Henry F. Oabom and Mr. Lawrence M. Umbe. wa. publi.hed in 1902. 
 
 The prea^nt part, continuing the wrie. of dewripti-e and illuatrated quarto 
 memoir, on foMil V.rtebr.ta of the North-we-t Territory, -on.i.t. of twenty.u page, 
 of letter-prew with text figure, and eight photogravure pUte.. 
 
 ROBERT BELL. 
 
 { XJOICAL SUBVEY DlPAKTMBNT, 
 
 Ottawa, June 22, 1904. 
 
•»l -^1' 
 
dKOIiOCSICAL SIIHVKY OF CANADA 
 
 ON DityPT()8AURD8 INCRASSATUS (Cf i). FROM THE EDMONTON SERIES 
 OF THE NOKTH-^H "T TKRKITORY 
 
 Bt Lawrence M. Lauhe. 
 
 Sinre 1824 .in Mtgalntaurut wiut first Hwi<rihed by BarkUnd • our knowledare 
 of th.' witpology ni tho.»rnivoronidinoii»uni hw be^-n in.rPiwinK iilnwiy yt with pn.our- 
 Aging inrety. For thu knowledge, no laboriounly gained, w.- are indebted to many 
 nthuaiantic workera on both lidea of the Atlantic-, amongat whom, have b«en, and are 
 at the present time, noinc of the moat noted and eminent men whose namen are inae- 
 parably linked with the progreae of vertebrate palipoutology. 
 
 A splendid advance waa made when Mamh in 1884 pnbiiMhed hia dewription of, 
 CfrnloMuruf natienrni* »* from the ll|.p.-r .lurawii. of Colorado. Mu.h that had pre- 
 vion»ly been either little known or imperfectly underntood. regarding th^ ftrii. ture ..f the 
 Kkull. was then mad.- .leir. The finding of moderately well preaervod sknlla of . arm- 
 voroua dinosaura ban been of an<h rare occnrren. e or the part». dia. overed have generally 
 been no fragn entary, that the re<-o- -troetion of the ■ Hire akull of ho large and interesting 
 a form as CeraloMHru* was of the gi 'est importar ;ei. without considering the almost 
 (omplote knowledge gained of the remainder of tlu eleton of that xpe.^ies. 
 
 Nearly related to CtTalosaurus i< the I'pi-Jr Cretaceous Drgplo$aurm> *** the type 
 of which Cope'a Lidapi aquilun^uit » froi<- hr On'ensand of New Jersey, was first d.s- 
 cribed iu 1866. Another sp -•• of Dry,, fiiruf is the western form D. ineraiiatu; tt 
 from the uppermoat beds of .• i- Vetai-eons « item (Edmonton series), described by Cope 
 at a later date. Anoth-r form l.om a lower horiion than Dryplmiturui, and probably 
 generically distinct, is the imperfectly known Dtinodon ttt of Leidy from the Judith 
 River beda of Montana and the Belly Rirer series of the Canadian North-west Territory 
 (Red Deer river, District of Alberta). 
 
 • NMioe .m th. M.«.la..uru. or grPrt K—il Lit."! -^ ?",•"-«;"• ^ ']^, "SV .■**"■»"• »"'^'-'"'"'- >''•«•''■• •''-*'■ "'"" 
 ««ti.mii(.fth.-Oeola|[ic»lH<iciBty, London. i<eoon<lMri.«, vol. 1. p. 31».pl»..\I^■^I-IV. , ,j „ 
 
 nn^ ArtM, thin! i«eri*«. vol. X.W'II, p. 329. ,. . ,_ .. 
 
 •••Ammcn iuurn.1 of .Vi^w »nrt Ar* thir.1 m-T\», Vol. .XIV. p. US, IS77. In .f.«t noU- M.r.h h«rapKH«<». the n*m. 
 
 /<r»l>«Mn«fn.l lo repUoc £.ri<ip«, C..l»', preoccupitirt. ....,„,, „. .a.^ 
 
 t ProoMding. ol th« A<»dMny of N.tur.1 8ii.nc~ of l-hiMeli*i», Vol. W III, p. J7S, !««•• ,.,„.. „ , 
 
 t1 .h. th« Skul! .*.th« I>in.«.i.ri.n Otlnp, n^numlu,, Cnpe. Pro««din(j. of th. An-nran PhiL-ophicl Soci.ty, Vol 
 
 V y V n 240 f W2. 
 
 m Pi«Mrfing« of th« Academy of Naturnl Sci«iwet ..» Philadrfphi*. Vol. VIII, p. 72, IHM. 
 
Cope, in October 1876. proposed the name L^lnpt incrassatus,* for teeth collected in 
 BnppoMd Fort Union beds in Montana (later referred to the Judith River formation), and 
 in December of the aame year he assi^rned a nearly complete dentary bone with teeth 
 from the same district to his species. In 1892 the same author published a description 
 (see foot-note p. 6), of two skulls from the Edmonton series of Alberta, identifying them 
 with L. inera$$atu>. It is likely that the teeth, and the dentary bone, from Montana should 
 properly be referr.'d to the large carnivorous dinosaur Deinodon horridus, Leidy, of the 
 Jadith Biver beds of Montana and of th. Belly River series of Alberta, in which case the 
 skulls from the Edmonton series would become the types of Dryptosaiirui incratsatut. In 
 part II of this volume it has been pointed out that Deinodon horridut is in all probability 
 generically distinct from Dryploiaurut inerassatun of the Bdmonton series. 
 
 The description of the two skulls of D. incratsatui by Professor Cope was read 
 before the American Philosophical Society in May 1892 and it was this gifted author's 
 intention to supplement what he had already written by publishing an illustrated memoir 
 giving the resulto of a further study of the remains. His purpose had not been carried 
 into effect, however, when unfortunately his death occurred in 1897. 
 
 Remains of D. inera$$al^>s from the Edmonton sories of Albfta form the basis 
 of the present memoir. They consist of the skulls, above mentioned, with some other 
 parts of the skeleton, which have been in the possession of the Geological Survey of 
 Canada and on exhibition in its museum for some years. The skulls are of special interest 
 and are the only two of this species known, so far as the writer is aware. They were 
 obtained in different years, from the same horizon, at localities a few miles apart. The 
 first was found, during the summer of 1884. by Mr. J. B. Tyrrell, on, and about two miles 
 from the mouth of. Knee Hills creek, a tributary of Red Deer river, whilst engaged in a 
 geological exploration in the Districts of Alberta, Assiniboia andSaskaehewan. Th.- second 
 representing a slightly smaller individual, was discovered by Mr. T. C. Weston in 1889 
 on the east bank of Red Deer river, at a point about twenty-one miles above the mouth 
 of Knee Hills creek, whilst making a collection of fossils in the Red Deer river country. 
 With the remains of the second skull and probably belonging to the same individual, Mr. 
 Weston found the distal end of a right tibia with the astragalus, a metatarsal bone, three 
 ungnal phalanges of the manus. a neural spine and a large portion of a left ilium with 
 the neural arches and spines of sacral vertebrae. Both of the skulls are crushed and dis- 
 torted and both are incomplete. Some portions are in an excellent state of preservation, 
 especially the rami of the mandible of the smaller specimen, which in part compensates 
 for the injury the specimens received whilst being removed from the rock in which they 
 lay. 
 
 The Edmonton series, defined by Tyrrell in his report on the geology of northern 
 Alberta,** as the lower of his two sub-divsions of the Laramie rocks of that region and 
 a« constituting the uppermost beds of the Cr»taceous system as there exposed, consists of 
 brackish-water deposits, 700 feet in thickness, overlying the marine Fox Hill and Pierre 
 group conformably. The upper sub-divison, the Paskapoo series, comprising beds of 
 fresh-water origin and reaching a thickness of .'5,700 feet, was . onsidered to be of Tertiary 
 age. The Edmonton series is representee, by " soft whitish sandstones and white or gray, 
 
 • Frucesdingii of the Acadrmy of Natural Hcienceii of I'hilBdrlphia. Vol. XX VIII, |.|>. 2** and S40. 
 
 -*Ji'l?"JI,f''*' JHl'l'*'""?' "'.""'■'' ^'"^^'^ °' ';«."»H«, new «.ri«. v„l. II. I8S7 (Annual R^|„rt, lSH«),",«rt E, K«twrt on a 
 part of Northern Alberta and portHmn of adjao-nt Ih.trict. of A»«nili..i« and Sankatchewan. '• i ' f. ■v.i«jn on a 
 

 • 
 
 
 
 
 
 
 
 
 
 
 
 
 
 often arenaceous, clays, with bands and nodnles of day ironstone and numerous seams 
 of lignite ". It corresponds to the lowest portion of Dr. Dawson's St. Mary River beds * 
 of the region more to the south and to the Wapiti River group ♦* of the country to 
 the north. According to Tyrrell the Edmonton series is essentially the .!oal-beariug 
 horizon of this district and underlies a large extent of country. To the west it thins out 
 and disappears beneath the overlying Paskapoo series and is apparently absent in the 
 foot-hills. No dinosanrian bones have been found above the Edmonton series ; a fact, 
 that, taken together with the lithological characters of the rocks, the manner of deposition 
 of the same and the palasontological evidence generally, led to the separation of this 
 series from the hiirher Laramie rocks and to the belief that the Paskapoo series marked 
 the beginning of Tertiary times. On the evidence of fossil plants alone, Penhallow t 
 comes to the conclusion, and supports Tyrrell in his contention, that the Paskapoo form- 
 ation is of Eocene aj?e. 
 
 The reader is referred to the publications of the Geological Survey for an exposition 
 of the geology of the western plains, and principally to the reports of Dr. Dawson, Mr. 
 McConnell and Mr. Tyrrell, in which the position of the Edmonton series, and its sup- 
 posed equivalents, in the geological scale, is discussed in some detail 
 
 General desceiption ok specimens, 
 
 Of the skulls from the Red Deer river district, the one found in 1884 on Knee Hills 
 creek is somewhat larger than the other. In this specimen (plates IV and V) the arches 
 are missing with the entire upper part of the cranium from the parietal region forward. 
 The brain case is preserved, with the bones of the palate behind, as well as the posterior 
 lower portion of the maxilla- and the anterior half of the jugals. The two rami of the 
 mandible are almost entire. The specimen is crashed downward, and what remains of 
 the upper part of the skull is distorted to the left, with the two rami of the mandible 
 Iving turned over, beneath. The two halves of the jaw have been displaced, posterioriy, 
 so as to partially expose the bones of the back portion of the palate in the space between 
 them. This displacement of the .jaw has brought to view the inner surface of the right 
 ramus, which lies, posterioriy, almost in the same plane as the exposed outer surface of 
 the left ramus. From this specimen we gain information regarding the form and con- 
 struction of the braiii case and the anterior part of the lower or infratemporal arcade, 
 the comiwsition of the palate and the shape of the several elements of the mandible with 
 their relations to each other. 
 
 The second and smaller skull supplies to some extent the deficiencies of the cra- 
 nium of the larger skull. In this specimen (plates I, II and III) the lateral parts of the 
 facial region are preserved, from the orbits forward, with most of the jugal on the letl 
 side. The nasals are apparently missing and, with the exception of a small piece of bone 
 on the left side, the premaxillie are not represented. The two halves of the lower jaw 
 are turned sidewav s and pressed against the palate, so as to hide from view the inner sur- 
 face of the left ramus and the outer side of the right one. The left ramus is preserved 
 
 ■ <:e.,l.«io«l »!..! NHtnml Hi.tory S„rv,>y uf rana.!.. R*|..rt of Progr™.. ISff- HSM. R-|..rt on th.. Kymn in the vieinity 
 i.ftliH B..W anil IWlv ri%.r», North «e«flVrril..ry. |i. na. lion. , „ .: . v, 
 
 •■ UM. Kn«'rt ..f l'.-.«r-»» for 1ST!' «i, K.|«.rt ..n un -xiJoral fr I'..rl Si„,iw.n ..n th.- I'ac.h. ,-.j«»t. U, Mnu.nton on 
 
 the Sa^katchfwan, 11. 124 H, 1»<1. .,.%.. ... 
 
 I Hmiv«linK»»n.lTr»n«.tio r thn Koyal S,.i,.ty of Canada, »«.-mil «■...-. >nl \ III, ».l.on I \. .Vole, on ( t.t*'«,u, 
 
 anil Tertiary plauts of Ciuiatla, p. 07, !»«■ 
 
for about three-fonrth* of ita entire length and the right ramas is broken off at about its 
 mid-length. The palate has been crushed upward against the uppar part of the cranium 
 and lies between it and the lower jaw ; part of it is exposed to view in the large preor- 
 bital Tacuity of the left side. 
 
 The most obTions features in the skull of Driplotnurut iwra$uitui are, its depressed 
 form above, the presence of two preorbital o|>euiugs (agreeing in this respect with Crto- 
 aauntt) and the large proportionate nize of the mandible compared with that of the cra- 
 nium. With some allowance for crushing, a restoration of the skull, tig. A. p. 25, gives 
 its length as nearly twice as great as its height. Its probable maximum width is equal 
 to about three-fourths the height of the skull but considerably greater than the height of 
 the cranium. In side view the general outline is roughly elliptical but decidedly pointed 
 in front. When seen from above, and again allowing for distortion, the general outline 
 is a long oval, truncated posteriorly, with tiat sides and narrower <n front than behind. 
 
 In comparing the skull of this species with that of Ceraloiaunm na»icornis. Marsh, 
 the proportions of length to height in both are about the same but the jaw in the former 
 species u much heavier and the facial part not so elevated. When viewed from above 
 the width and \e aiiount of elongation, in both species, is somewhat similar. 
 
 In the form of the muzzle D. incratsalus apparently approaches more nearly the 
 Upper Jurassic species Creosaurus alrox. Marsh lately described *by Professor Osborn from 
 two specimens from Bone Cabin quarry, near Medicine Bow, Wyoming. 
 
 
 The smaller skull. 
 
 Considering first the upper portions of the skull of the smaller specimen (plates I, 
 II and III). The maxilla is a large, robust bone of considerable height in front. It 
 narrows rapidly backward below, terminating posteriorly in a sharp point. Anterlorlv 
 its border curves evenly upward and backward. On the left side the premaxillo-max- 
 illary suture, PMS, (plate I), is seeir for a short distance upward from the alveolar border. 
 A small piece only of the premaxilla, PM, is here preserved, and in it is the inner side of 
 the base of a moderate sized tooth. Beyond this no indication of the premaxillu> is 
 observed and they are presumably for the most part missin*^. The nasals are also thought 
 to be absent, or if not, at least preserved in so fragmentary itate or so crushed as to be 
 unrecognizable. 
 
 The jugal succeeds the maxilla behind uniting with and slightly overlapping it 
 in a long, very oblique suture. It throws upward from its superior border, near its 
 anterior end, a procees that meets a prolongation downward of the prefrontal bone. This 
 divisional bar, in which the lachrymal is probably included, separates the orbit from a 
 large preorbital vacuity. The latter opening is of large size, is subtriaugular in shape 
 and approaches close to the superior border of the skull. Its upper anterior margin is 
 formed by the upper posterior extension of the maxilla. Below it is bounded, in almost 
 equal part, by the maxilla in front and the jugal behind. In advance of the preorbital 
 fossa is a relatively small opening, APV, the anterior preorbital or maxillary vacuity, 
 somewhat broadly oval in outline, separated from the larger opening behind by a nar- 
 
 'Bulktin of the Amorioui Miueum of N»tur»l HiaUiry, v<il. .MX, articlf X.\.\I, pp. (i97 701, iaU3, " The 8kull of C'rw,. 
 
row bar of bone. The surface of the bone, along the lower margin of the preorbital 
 vacuity and surrounding the smaller opening, is smooth and depressed, forming a mar- 
 [jtnal tract at a lower level than the general surface of the bone. This depressed area is 
 also continued along the anterior upper border of the preorbital vacuity for a short 
 distance. 
 
 The large opening, here regarded as the preorbital vacuity, was described in the 
 preliminary report by Cope as the orbit. The present writer is, however, of the opinion 
 that the orbit is to be found in the opening farther back in the skull and thiit Dryji- 
 tnsiMrut had, in common with the ancestral typi- CreoMurux, at least two preorbital 
 openings. 
 
 DryptoMiurus iucransatus has, hitherto, been considered rather exceptional in the 
 possession of, and in differing from Ceralomurus in having, so large an orbit placed so fur 
 forward in the skull. With the present interpretation, the orbit is in about the same 
 position as is that of the latter species and also that i>f Creuaaurus. Ceralotaurut nasicornis 
 is described as not having an aperture in advame of the preorbital vacuity. In an 
 examination of the skull of this spe.ies in the National Museum at Wa.shington, D.C., 
 the writer did not observe a second, smaller op«'ning in advau<'e of the preorbital fossa 
 nor was an indication of such a structure likely to escape the notii e of so accurate an 
 observer as Professor Marsh, althougli, in his published figure, a decided depression is 
 shewn nea- the upper edge of the maxilla immediately under the nasal horn core. 
 
 The number of teeth in the maxilla was apparently twelve ; of these the bas.-s of 
 the lirst four, the sixth and the twelfth are preserved; the fifth and the eleventh 
 are entire. Between the sixth and the eighth (of whi>h about half the <rowu is 
 preserved) is sufficient space for one tooth, the seventh, and another space between the 
 eighth and the eleventh, indicates evidently where the ninth and tenth were lodged. 
 
 The tooth, already mentioned, of which the inner side only of the base is seen, in 
 the outer lateral portion remaining of the left premaxilla, is in the position of the third 
 incisor if each premaxillary bone held three teeth. 
 
 Above the preorbital fossa is a t- branched bone interpreted as the prefrontal, 
 PF. It consists of a prominent knob, flattened above, from which proceeds a horizontal, 
 forwardly directed limb lying above the preorbital vacuity and a vertical part that 
 passes downward to meet the process of the .jugal below. This bone, posteriorly, over- 
 hangs, and forms part of the upper anterior border of, the orbit ; its vertical limb with 
 the upward extension of the jugal separates the orbit from the preorbital opening. The 
 horizontal and more robust portion of the bone projects over the preorbital fossa, forming 
 its jwsterior upper border, and tapers rapidly forward to a sharp point. It is impossible 
 to tell from this specimen to what extent the nasals are developed as no portion of them 
 can be recognized, indeed, it is extremely doubtful if they are at all represented in the 
 fossil. .Judging, however, from the curve of the upper anterior margin of the maxilla> and 
 the narrowness of the space between the preorbital optmings (no doubt greatly reduced 
 by distortion) they ai^ thought to have been long and slender, extending almost as far 
 forward as the maxili;e and extending back to a point midway between the posterior 
 prominences of the prefrontals. With this length allotted to the nasals the premaxillie 
 would have been short. 
 
 2 
 
10 
 
 The exterior surface of the maxilla is rough and a few foramina, occnrring at 
 intervals (as shewn in plate II), not far distant from tlie alveolar border, an- conspicuous. 
 
 The jngal extend* forward for some distance in advance of the posterior termination 
 of the maxilla, meetiag the latter in a long, oblique suture, and slightly overlapping it 
 It narrows rapidly to a point in front. Back of the orbit it throws up a process, POB to 
 form the lower half of the postorbital bar. U is of considerable depth below the orbit but 
 IS not preserved to its posterior termination. In plates I and II, the emargination of the 
 bone at a indicate* the curve of the lower front margin of the infratemporal fossa. 
 
 Within the preorbilal vacuity on the left side are preserved certain bones (plates I 
 and II, b, e and d) which are spoken of, in Cope's preliminary description, as the orbito- 
 sphenoid, the postoptic and the epipterygoid respectively. The present writer beli.-ves 
 that the bone h is the left element of the paired vomers (the prevomer of Broom*) 
 Posterior to the vomer is what is thought to be the palatine (c and d) as seen from above 
 fractured so as to be easily mistaken for two separate bones. The space between the 
 palatine and the vomer evidently represents the internal nares (I X, plates I and II) and 
 the concavity behind the palatine (corresponding with that seen in the larger skull) a 
 suborbital vacuity (S () V, plates I, II and III) of considerable size bounded posteriorly 
 by the transpalatme (ectopterygoid). Further reference will be made later to this portion 
 of the palate in the description of the larger skull. 
 
 Passing to the mandible ** it is only to be regretted that it is not entire. About 
 three-fourths of the left ramus and half of the right ramus are preserved iu a very excel- 
 lent state of fossilization. Fortunately the right ramus has shifted its position so as to 
 exhibit the elements.omposing the inner surface, except in the symphyseal region where 
 the two rami lie against each other ; behind they have opened like the blades of scissors 
 The outer surface of the left ramus is almost as perfect as could be desired, from behind 
 the highest point of the upper curve of the surangular, forward. The left ramus exhibits 
 the greater part of the dentary, 1). and a large portion of the surangular, SA, the denlary 
 passing beneath the surangular. The surangular is broadlv arched above, as seen in 
 side view, Us .urve continuing forward into the reversed curve of the alveolar border of 
 the <ientary This latter bone is narrow anteriorly, its lower margin being for some dis- 
 ance back from the symphyseal region, parallel to the alveolar border. In front its lower 
 border curves obliquely forward and upward. The symphysis is hidden from view in 
 this specimen. The greatest depth of the dentary is reached where it meets the suran- 
 gular above, the suture between these two bones curving evenly downward and back- 
 ward 80 as to reduce the depth of the dentary rapidly as it passes beneath the surangular. 
 
 The outer surface of the dentary is rough and exhibits a number of foramina and 
 vaacular grooves, the latter of which l numerous and particularly conspicuous anteriorly 
 (plate III). Farther back near the surangular the surfa.^e of the bone becomes quite 
 smooth. Some of the foramina follow the upward curve of the dentary iu front • the 
 remainder are in a rather regular line below the alveolar border. This foraminnl line of 
 the same length as the dental series, is slightly over an inch below the alveolar border at 
 Its mid-length ; it approaches closer to the border in front and behind. The foramina in 
 
 • Pnii'««iinKi. nf thf I.ililiHan IS.k;i.ii of Nin .Hiiiith \Vale«, 190.1 n,l .\VVII 
 VimienlM! Umw, \: r>».\ by K. Hnniii. , > i. .x.x » ii. 
 
 •■ Th, 
 
 ' < til tlif .Mikiiiiiiiilian and Ki'ptiliati 
 
11 
 
 this line are conneoted laterally by a nearly lontinnous groove from which a number of 
 short, deep grooves u,e given off at right angles ^ extend upward toward the alveolar 
 border. 
 
 There are fifteen teeth in the left ramus, agreeing thus in number with the supposed 
 number of maxillary uuu premaxilhiry teeth combined. Fourteen full-sized teeth are 
 preserved whilst in advance of the anterior one a small tooth, e, partially protudes at a 
 lower level. This tooth is uppar«nM" an additional one in the series and not a suc.essional 
 tooth, making the total number in the .omplete dental series, fitteen. It is truncated 
 posteriorly so as to be similar in this respect to son of the teeth described by Leidy, 
 under the name Deinodon hnrfidui as being peculiar in form, * and to a tooth referred to 
 by the writer in his description of Ornilhomimu* nltua t as being from the anterior por- 
 tion of the jaw. 
 
 On the inner side of the right ramus the front part of the splenial, SP, is seen pre- 
 .eded by a narrow presplenial, PSP, which extends forvrard between the dentary below 
 and the alveolar plate of the dentary, DP, above, to the symphysis. 
 
 The splenial as shew.i .n this specimen, if a deep lamellar bone, immediately above 
 the dentary and Ol•^upying nearly the whole depth of the ramus, from its upper border 
 b. hind the dental series downwanl, cutting off the alveolar dentary plate posteriorly and 
 greatly diminishing the depth of the dentary behind. It is obtusely wedge-shaped v.i 
 front passing below the presplenial and terminating in a sharp point a short distance m 
 advance of the posterior end of that bone. It is perforated near its anterior end and close 
 to its lower muririn by a large oval foramen. At a short distance behind this foramen, 
 in the line of the •, Ttical fracture, a well marked emargiuation (/, plate III) oi" the bone 
 o<vur8, that is -hewn, however, to a greater extent and more decidedly in the specimen 
 fio-ured in plate V. The outline of this emarginatinn bears a strong resemblance to the 
 anterior end of a second foramiual opening, which, if it did exist, may have been partly 
 enclosed by the angular as in Croroililm. A transverse section of the lower part of the 
 spleni a is seen at «, plate III, in the left half of the jaw. 
 
 The dentary o<cupies about one-half of the lower depth of the inner sunace of the 
 jaw anterioriy, narrowing backward gradually below the splenial unti. it disappears from 
 the inner side altogether. 
 
 Above the presplenial the inner alveolar plate of the dentary. of somewhat greater 
 depth than the presplenial, forms the inner wall of the den al chamber and completes tne 
 inner anterior surface of the ramus. It meets the splenial posteriorly and narrows rapidly 
 upward, but its relation to the dentary and the splenial, behind the dental series, has not 
 been ascertained. Its upper border is at a lower level thai; the outer alveolar border of 
 the dentary.. The full d.-pth of the dentary plate is seen at g where the inner —.face ol 
 a tooth rising above its border, is just hidd<'n, in a direct side view of the .nan< such 
 
 as is shewn in figure 3, by the lower i dgo of the dentary of the left ramus. 
 
 •T™nMction«ofth- m.ri.anl'lnl....pM€»lS.«iMy. Extinct Vertrbmu. from the Judith River an.l liri-M Lignite for- 
 mation, i.f Nft,r»«ka, by -I."*!* I..idy. \m>, p. IH. p'— «, tiK". -I"*', 
 t I'art II iif thi» volume, p. .W, iil.-itf .\!V. 
 
IS 
 
 MtaimremenU of nnalhr »k\M. 
 
 MM. 
 
 Msximum length of Hpecimen (length of left ramuH preserved) CIO 
 
 Mkxinium thioknei!) of Hpecimun ; from poNterior end of prefrontal U>uuter surface 
 
 of left ramus 2IO 
 
 Maximun. breadth of specimen ponleriorly 4U' 
 
 Breadth of specimta at eighth maxillary tooth 2'JU 
 
 Kxtreme length of left ma-.illa 4.'i; 
 
 Length of left preorbital vacuity ' 190 
 
 Width of same yn 
 
 l«ngth of left anterior preorbital vacL^ty ... 63 
 
 Width of name 43 
 
 Distance from lower margin of anterior preorl-ital vacuity to alveolar border of 
 max=!la 
 
 Length of dental series of maxilla 
 
 liCngth of dentary, above, to its junction with the surangnlar 
 
 Depth of dentary at its junction above with the surangular 
 
 Depth of dentary below the tenth tooth 
 
 I^ength of d»ntal series of dentury 
 
 Depth of inner alveolar plate of dentary at g, below the 1 tenth tooth, plate III. 
 
 Depth of presplenial below g 
 
 Depth of dentary below g (+ depth of anterior end of splenial --- 4 mm.) 
 
 Distance from alveolar border of dentary plate at y to lower border of ramus. . . 
 Diffrrence in level of inner and outer alveolar borders of ramus at tenth tooib. . 
 
 Length of crown of fifth maxillary tooth 
 
 Breadth of same at base 
 
 Thickness of Hame at l)ase 
 
 Length of crown of sixth tooth of lower j>iw 
 
 Breadth of sumc at base ... ^ 
 
 Length of iTiiwn of m^venth tuoth of lower jaw 
 
 Breadth of crown of same at l>a»o 
 
 Length of crown of eiglilli tooth of lower jaw 
 
 Breadth of crown of same at Ijase 
 
 Length of .splenial foramen 
 
 Height of HHUie 
 
 Distance between splenial foramina 
 
 Ill 
 
 .130 
 
 S30 
 
 160 
 
 9(! 
 
 325 
 
 33 
 
 17 
 
 48 
 
 88 
 
 8 
 
 49 
 
 14 
 3« 
 18 
 55 
 •1\ 
 46 
 21 
 52 
 30 
 47 
 
 The r,AR<tKR skull. 
 
 Owing to the prf sure that has been exerted on this specimen (plates IV and V) 
 obliquely downward iron, the ..ght, the cranium is distorted to the left and the man- 
 dible has turned over sideways beneath the cranium so that the left side of the left ramus 
 and the inner 'side of the right ramus lace downward. The two halves of the mandible 
 have b» n forced apart, anteriorly but little, posteriorly to a considerable extent so as to 
 expose me bones of the palate behind. The brain case is preserved, also the posterior 
 ends of the maxilltc with the anterior part of each jugal and, as just mentioned, some of 
 the bones of the palate ; with these exceptions almost all of the other parts of the cranium 
 have disappeared. 
 
 The roof of the brain case appears to have been horizontal in lateral aspect above and 
 to have been met posteriorly from below by the plane of the occiput at slightly more 
 than a right angle, the latter being not quite vertical but inclined slightly backward. 
 
V) 
 in- 
 ns 
 >le 
 to 
 or 
 of 
 m 
 
 IS 
 
 I. wa. anKuUte in the m.^ian line abov., at lea-t .nterio.ly as » J'^-^^^'y ^'J^ J"'«; 
 1 ,n 14 rv .r,A ti<r Ifi nlate VII) of whirh the front ends remain, ine upper 
 ur'iir; StZt^ttnl^Ziiol large extent, but on either «ide of it. longitudinal 
 a, X nm!^r facea of the au^temporal va.nutie.. A. plate IV. partially remain ^ew- 
 h!i that W ;j^ning« were small and situated . loae together at about the n»d>ength of 
 Z Zm! Xr* remain, of the inward sloping surfaces of the aupratemporal fo^...- nhew 
 ttatTparietal here met above to form a very narrow angular nd«e m-n^uiuation 
 backward of the median angulation preserved in the anterior part of the parL-Uls. 
 
 In the occipital .egion, plate VII. fig. 16, the exoccipitaln and ^J" *>"'-'^^3"»; "^ 
 represented but the supra-occipital is missing. The occipital condyle is considerably 
 broX tSu high, somewhat angulated below . ansversely, «hallowly excavated abo^^ 
 Sndinallyin continuation of the floor d the foramen magnum and present, a well 
 rZd^d arti!;,", .nrface pointing horizontally to the rear. Bo.h the foramen magnum 
 and the occipital condyle are small. 
 
 Th, sutures between the bones of t..e oc.ipnt have not b..en detected so that the 
 limits of the difl-erent elements are still ,bs.ure. A prominent flange of bone directed 
 bakward and outward, forms the lateral boundary of the oc<-.put on either side as seen 
 from behind. On the inner side of this flange, between it and the basi-occip d, occurs 
 adeep tossa which is the outer termination of a pair of foraminal -P^^'^'f'.^l''^^'^' 
 occipital condyle the basi-occipital presents a vertical plane .urface, standing out pro- 
 minently between the fossae. Its breadth is less than that of the condyle and le s t^han 
 that of ils own downward extension ; unfortunately it is broken below. The exoccip.tals. 
 of which the lateral flange forms a part, bound the foramen magnum Ir.terally and above. 
 On either side of the o<cipital condyle are two foramina, one of moderate si^e, at a h.Bher 
 level and farther out from the condyle than the oth. which is qrate small. The larger 
 opening wa. pn.bablv lo: ^ho transmission of the n.rvu. .v.^'vs r>r /''"•'""--"f-'^ '•'':'• 
 V fiK If. plate VII, IhesmalW one, judging from its position .mmcdiately behind the 
 vagus, is thought to be the io. len Tor the accessary nerre, XI, which made its hrst 
 appearance in the reptiles. Below thes*, foramina and occupying the inner end of the 
 deeply excavated fossa are two openings, of equal size, side by side, separated from ea.h 
 other bv a thin partition of bone. One of these may represent the hypof^hssal loramen, 
 \II on account of its ventral and posterior position, the twelfth or hypoglo»al neroe 
 ansin- from the lower aspect of the medulla behind. The other opening of the pair, may 
 be ih.lcnrotid foramen which in the crocodile is somewhat similarly placed. A...erior to 
 the lateral flange of the exoccipital are two other large foramina, one above and consi- 
 derably in advance of the other (see plate IV) A deep groove in the bone leads 
 forward to the hinder opening which forms its front termination. The upper and /ron 
 oi«.ninR is regarded as the foramen ovale through whi.h the tri^emin.,1 nerve { F plate 1\ 
 passed out of the skull, the other one probably provided for the exit of the /«««/ and 
 auditory n,rce>, VII and VIII, which are to be looked for a short d.stan.^e behind the 
 trigeminal. Cope in his reference (in the preliminary description) to the same two fora- 
 mina expresses the opinion that " one or both of these is the trigeminal . 
 
 The supra-occipital is not distinguishable and has probably been entirely removed, 
 or if presp-t in part, is crushed bef ond recognition. 
 
'■^ ■ 
 
 14 
 
 PaH^inif (o th.. low.-r 8urni... „fth.. brnin ■•«.. 
 
 ba.i.ph«„„ia ....men. of.L ha^t^l K r ^X:!' "'h^ l"" ,"?"'" ""'""" "^ "«<' 
 
 r.;g,.rd..d a« „ pituitary lorum..,.. I,. advatJ .^.H l"'"'!''"'^ ' '^^ ''^^ 2''' P'*' '*^"1> 
 d.Ht».u... Iron, he,...„th th- pituiturv »or, „an „r! k 5" '•' T""""' « ^"'^"'^ ' ' «>">« 
 preHumably th.- v-aeriparLphenoid . S V" 'f^^'/^r °' "'"^ "npaired bon... 
 of th.. «p«oiu,en. would ho i„ i,. p ' . ..ol ,t .ITh ' ? '' ''""^*"» '""^ ''"' «l'«»"rtion 
 
 Pitu.ury foramen, rlos. ,o and .light J ." ,£ " J P' "" "'""" '*''" "^""^ 
 
 wh...h a small '-am.^n l.ad« upw,.r. ^//Z^a' 'li /;;P ''"P--ion from 
 
 nerre^,y,„ otf from th.. v..ntr«l r.-non of .L mid hraii . ""■ '**'"' °' '^"'"^'^"^ 
 
 .he ..... ... . ..,„,.,, ,.,^^,,,^^ „, eh";i:r:nh.:i-;^;^:^^^ ^^ 
 
 ..eorSt^d";^;:^:;^?'::;^ tLr:;::';^^" ''^r "•-- '^e mid.,e„,th of th.. 
 
 •h. lin.. of fraHur.. whi.h .on.inn .;'. ro . h .^7 T."'" '''V''''' • *" -''—'"• 
 of .he mux^lo. On .-ith.-r .ide about one trd„nh ''■ """""'^ ^^'"''^'^ '" '"ft 
 maxdla from behind, th.. suture betwee t h, tt K 'T' "''"*'"" "^'"''"PPing <he 
 -«« (*, plates IV and V). On th.. r Iht s de " *"""* "'^'" P''"'"^^'! '« ea-h 
 
 and fo....d inward into ,h.. orbiul .".In n^^^ ' '"'^.C 'I'b '" ^'"'"" ""*• *'«''" '^''P'-^ 
 "f the .p,g„I imm..dia.ely beneath th.. Fa..h X^f^ °".«' °;P«««ihIy that portion 
 d«pl.u-ed fragment ,L. p.ate IV, ,nd indi..a,..;jbri„;itit':7;h'e"ottTb h'"d "' ^'^ 
 
 (.■olj;:;i;~?'1?t:u;:!;r,:fL:'^^" ^7- ■^- ^-e^-dedastheepiptery^oid 
 
 » hidd.. bu. is apparentiyV.:!. :,;: ;:;';;'^jppr:'';'f;^^ lei/owerd 
 
 dun.„.shin,..liam..terto,hen..i..hbourhr.do ;h..CS^^^ '' 'T'^ "'"--'^ with a 
 p..in(.np outward and sliffhtly backward A , ' ''''"•^^'^ "PPer termination 
 
 -all..r skull and exposed" n L ^rH^Z pi: '^TJl ^."ir' '""'■• P^^-^"^ '" 'he 
 the fig,„,8 of plau.8 I, H ,„d HI) i« ,h«u«ht •. o t^ h ,h '^"'■"""" '""^ ^•'''•'''" iM 
 
 ^^..-.other bones of.h.. skul, eann.^ -'i:^:!;" --^ ^ -' ^ -i-n 
 
 ture^t;:^;t:;;s?!;';tl::^t;:t^::'2^ xhe.™. 
 
 -orroboration. Also the relatione to .' h oth . ., t^ dil." VT""*^' ^''""' »""- fi»1« 
 oon.pos„.o„ of the posterior half ar.. ma.le .1 a 1, t o'T ''""*"' '^"'""'•^ '"''> 'J"' 
 of where the spl.-nial would Ix. exp.., ted to me. t' /h ^ " '"""' "'^^ •" 'he vicinity 
 
 The ..tent to which th.. angular i .^ve io^rol tVZ: '"',' *'"" '"° *'"' ~'d 
 n.al has no. been s.-en iK,st..riorly andlh. ,1 a Tl *"'" '' ""' "'""^n, th.. sple- 
 
 .— <!. ^v«n ,n part, in the rii.";!!:.; z'^^ 1:..:;;^:;: lUj^ '^" --- -^ ^^ 
 thei^^st.?-.;;:::;:;-'-^-^^^^^^ 
 
 the lower bord..r i« mis., iZ-J:^^-:, S'^ ^ ^ '■^""''^'-^''^ P^ - 
 
 X 
 
 am 
 
16 
 
 The mandible of D. ineraumtmt in dwper in proportion toil« K>nirth than that of Cera- 
 toiaurut naMiivrmin, nthfrvtine th<( i?en«r»l contour in both N|.fiii soint'What ainiilar. 
 
 The different boueH of the mandible seen, wholly or in part, in this liirger «kull are :— 
 the deutary, the nurangnlar, the uujfulur, the «rti<ular, the apleuiul and the prexplenial. 
 
 The dentory, iilrendy known from the Hniiiiler nkull to be ii lari,'e and robuf bone, in 
 here found to extend barkward to beneutli the articnlar <otylu>. Alter attuiiiinjr ilx 
 greatest depth at al>out its mid-length, where it meets the Bnriingular abovi-, it passeN 
 bat^kward below that element and overltti>ping it posteriorly as a thin plate, terniiniitif. 
 in an acute point (plate V). As already seen, the d.'Utary, on the inner siirfaee, o(Cupies 
 about one-half of the lower depth of the jaw anteriorly. Its depth diminishes cradunlly 
 backward but the exaot point where it di8app.:irM from the inrier surface has not b«'en 
 ttNc.-rtained. It is thus seen that the dentnry of Dryptoiauruf in the amount of its back* 
 ward extension equals that of the deutary of Splie no/I'm and far r-urpa-ses that of Certitn- 
 
 The upper border of the suraugular i-xteiids in a low sweepinjj curve forward from 
 the articular lotylus above the level of vvhi« h its highest point is but little elevated. 
 This bone almost completes the rema-niler i>t the outer surfa >f the mandible, the pos- 
 terior end of the angular being visible inlVriorly to a limited extent with a still smaller 
 surface of the articular shewing behind. It is strenjrthened exteriorly n.-ur its upper 
 border, by a prominent rounded ridm'e extending for some distanc4' forward from the arti- 
 cular ootyluB into the composition of which it enters. A small boss of bone rises from 
 the superior border within the ba< k end of the riilge and in front of the outer end of the 
 articular cotylus. The surangular embraces the articular anteriorly, and passing beneath 
 it, extends as far back as the losterior limit of that element. It is piened by a foraminal 
 opening at about one-fourth ol its length in advance of itsbaik termination and at about 
 its mid-depth ; its inner surface in this region is deeply concave, fig. 21, plate VIII. 
 Below the foramen the bone becomes gradually thinner, where it is overlai)pcd by the 
 dentary, and is continued forward with a thickness, inferiorly. of only a few niilllmelr.s, 
 although posteriorly and along its upper border it is a stroiur and thick bone. 
 
 The articular is t^mall and compa.t, roughly triangular in shape, and is scarcely si'cn 
 except when viewed from above. It forms al>out two-thirds of the cotylus and is ..vcr- 
 lapped on its inner side by the angular, whiih extends nearly as far ba>k as either the 
 surangular or the articular. Its breadth exceeds its antero-posterior diameter. 
 
 The articular cotylus is transverse, deeply bitossate and evidently points to a striitly 
 upward and downward motion of the jaw, as the distal end of the (juadrate lits closely 
 into it. The movement of the jaw is, therefore, restrii'ted, anil differs from that of 
 Spheuodon, in which the articulating surface is nearly four times as great aiitero-posteriorly 
 as the condyle of the (juadrate and admitted of a backward motion of the mandible. 
 
 The slender bone meeting the snrunirular below the artici'lar, and embracing the 
 latter element on its inner surface, is regarded as the angular, of whiih mention has been 
 already made. It passes forward on the inner surface of the ramus in contact externally 
 with the inferior edge of the ])osterior extension of the dentary but is broken in both 
 rami at a point slightly behind the mid-length of the surangular, unless, as is strongly 
 suspected, its more anterior extension is sei'u more in advance at / plate \', where the bor- 
 
A.! 
 
 16 
 
 der of • luB«IUr piece of bone Mcenda, corresponding with that part of the auguUr that 
 would form the lower, and together with the roronoid the anterior border of the large 
 Tacuity in the inner aurfare of the ramaa. The break in both halvei of the Jaw at thia 
 point ia nnfortunate, aa it is here that the Janrtiou of the angular with thekpleuial would 
 hare been looked for. It it probable that anteriorly the angular invreaseR very roinh in 
 depth, reaching the coronoid above and the aplenial in front. 
 
 In thia speoimen thi* front part of the Hplenial ia diapUi-<-d and itM relation to the 
 dentary and the preaplenial ia not no well ahewn on intheamuller iikall. The emargiiia- 
 tiou of the bone behind auggeating the presence of a set'ond splenial foramen ia, however, 
 very marked (/ plate V) Its narrow, (Mjinted anterior termination, properly fitting )m-Iow 
 the back end of the presplenial, is aeeii piMaing up betwtH>n the rami {S V, plate IV). 
 
 The presplei i\ and the inner alveolar plate of the dentary are seen in loth rami but 
 the hinder end of the former ia hidden. In front, where the rami have separated slightly, 
 the outline of the presplenial is obscure so that it in doubtful to what extent it passed 
 forward although apparently it reached the symphyseal surfui'e at least. The alveolar 
 plate is slightly dt^i^er than the presplenial and together they altout ('<|unl in depth the 
 inner development of the dentary bt>low. As seen in the smaller skull the Npleninl pusnes 
 behind the alveolar plate so as to materially reduce its depth near the termination of the 
 dental series. In the larger specimen the alveolar plate, althouirh itM exact outline is not 
 seen in front, is nevertheless considerably reduced in Hiie anteriorly whi-re it would lie 
 expected to join the dentary from without. The symphyNeal snrliice is narrow and 
 extends, with the direction of the anterior border of the mandilile, ohH(|uely upward and 
 forward. The union of the rami as in all dinosaurs was liuamental. As has been already 
 mentioned the inner alveolar border was at a slightly lower level than the outer border 
 but the amount of difference in level is more exai-tly determinable in the smaller skull 
 than in this specimen. - 
 
 The outer surface of the mandible is rather smooth 'hroughont and in this respect 
 shews a marked difference to the jaw of the Hmaller skull in which the anterior part of 
 the rami are decidedly rngost*. The front {lortion of the surangular in striated aa xlievvn 
 in platb V. In the d-.>ntary a number of foramina are present, near its anterior lower 
 border, of a size and in disposition, as indiiated in the figure. Across this bone, at about 
 its mid-length, a somewhat obscure row of shallow depressions extends upward and 
 backward in an oblique curve as shewn in plate V above the anterior end of the break 
 in the left ramus. This feature is snggested in the dentary of the smaller specimen but 
 is too indistinct to be spoken of with certainty. 
 
 In MegalotauTfs * the bony partitions separating the alveoli from each other an> des- 
 cribed as springing from the inner alveolar wall and projecting outward to the inner sur- 
 face of the outer wall. The reverse of thi.s Neems to be the case in Dryptomiurus, in which 
 the principal alveolar grooves are apparently formed on the inner surface of (he outer 
 dentary wall with little or no development of grooves in the alveolar plate. In this par- 
 ticular the alveoli of Dryptnsaurus are slightly suggestive in general plan of structure 
 of those of the dental chamber of the mandible of the Cretaceous species of Trachodon ** 
 in which the teeth more upward in well defined grooves in the inner surface of the outer 
 
 •Trail*. *Jeol. Soc., London. »e«inil uerit^, vol. 1, p ;t!^. pin. XL ami .\LI, 1824 (full rcffffno* on p. 'ii uiiil "On theHkull 
 of Mi^aloMUrus.'' by ProfttuMir Owen. I^larttrly Jtxirnal I i,>o]uKifal Society, Uindoii. \t»l. XXXI.X. p. 3;W. p). .\l. LSSi, 
 *• Part II of thia volume, p. G9. 
 
17 
 W.1I of th.. dent.1 .h.mlM.r. .vhiUt th« »aff*« of th« inner w.ll ol th.. .•h.m»H,r i. ...m- 
 
 orm part of, ami to b. .ontiBU.Iiou. or .-xtenaiouK of. th.- inner .urta. .- ol the on e den 
 tary wall, inward toward the dent.ry plate with which they are apparently not Tery 
 ■trciiKlv (•onue''ted. 
 
 The teeth «f thi. .jHHieH (without referen.e to .uch an muy b». .on.idered to U 
 in.i.or.) are .armated on their anterior and iKH.terior ed,;.«. the rarinat.o„« »«''»B ;""'"'';'y 
 .errated, with about ten to twelve denti. ulution. in a ap* e of 6 mu.. I h.7 are lent., ular 
 inK,aion alK,^e (plate VI, fifr.. !»-14) but in pa«»in.r downward a "* '•""'8 "J ;' 
 anterior and posterior border* .ak.-n plu-e ami be. om.. mor.- pron.mn..-d n-ar the baa. 
 of the .rown, a alight flattening ol the »ide. of th.. teeth alno b....,m.«g more de.lded .1 
 the lower portion of the cn.wn. The anterior .urina ,,aa.eH gradually to ... '""'■'- •i'''' 
 he .rown whiUt the poat.r.orone i« w.ll over toward the out.r ..de lor the ;;reater part 
 of it. lengtr The po^erior keel exte.td. downward for the whole length of the .rown 
 but th.. anterior one atopa at about ..ne-fo, rth the height of th.. -rown Iro.n .t. baae. 
 
 In the left ramu« of the larger .kuU the .rownH of all th.- t..eth e». epl the tw..llth, 
 „, plaU-V. urebrok..n olf clom. to the alveolar border leaving ^...t.on. of ihe.r baH..» 
 xi.Hed at this level. .0 that the ...a.t ,>o.itio.. ,.f th.- ...th, in th.. ^^^^iU liZJ;^ 
 deH..itelyd..termined. In th.. right ra.u..., plate IV. however, seven ol the teeth a e 
 pr..Herved inta.t whil.t the baae« of the lir.t four and of the ..U.v..uth re.na.n ... p.^.t.o... 
 In all the ...eth of the mandible ex.vpt the a..terior one of eith.r rarau., th.. .nt..ro- 
 ,„,sterior diatneter of th.. baae ..f the crown is U-reater tha.. the tra.,sv..r«,. d.ain.. er I., 
 the front or lir.t tooth the se.tion of the baae shews that l.,' Iran.verae d.ameter was 
 equal to or if anything greater than th.. ai.t' -o-posterior o...- 
 
 Ko succesaional t.-eth have bee., observed, i.. th.- .wo skulls of Dm>to»auru» from 
 the Edmo.,ton seri.-., ex.ept one in the left maxilla of th.. lander sp.M-.m.n. ». plat.. V, 
 a..aa..other in the right maxilla of the smaller on-, ..ot sulh.-.eu.ly ..o..sp.c.,ous to l... 
 shewn in the figure, plate 1. 
 
 The lower end of the left quadrat.', fi-.'. V\ plate VII. is transversely elongate and fits 
 rlo...ly into th.. two oblique depressions of the arti.ukr ....tyhts. Above .ts urt.. .. ar 
 
 surfa.e the quadrate <o,.tra.ts i,.to u narrow n... W. retai..i...r a .ra..sverse d.am.ter gr. ater 
 tha.. the a..tero.posterior o..e. Us forward siirfu.-e is slightly . ..n.ave a..d when th.. b...... 
 
 " position th.. ..e.k is dir.vled obliquely upvvar.l a..d forward. I., h. r.ght ra.m.s 
 
 t.K i.!^..r surfa. o ..f the ..uadrate, Q, plate V. is s..e,. but mu.h .■r«sh..d a..d prcjmb y 
 dis'orted so as to -ive li.tl- a.-.-urate inform,.! ion as to .ts tr..- shap... although .t ev.denlly 
 was .-xpanded above to some extent and r.'a.h.'d the pterygoid. 
 
 In the palalal region the following ..lem....ts are repr..s..nt,.d or more or l.-sselourly 
 
 s..en, lro.n below :-th.. basisphe....id, th.. b»siptery..,oid pro. .sses o th.. .as.Hpheno.d 
 
 (basipt.rygoids), th.. pt..rygoids, the right transpalatit.e (......pterygoid) and the ba.^k half 
 
 of tl... right palatine. 
 
 The pt..rygoids, l>r, ar.. .,io.l..rat. ly large I.0....S, narrow a..t..riorly wh..re they appr 
 
 .0 .....et in the middl.. H..., ..f the h.ad. ThVy ar.. ev-oly rou...i..d ,u trout when- the.r 
 
 ...argins nuderli.- th.. palati....s. ,M a short .lista..... l...hi..a the.r front e,.ds they turn 
 
 3 
 
Il 
 
 bil^i^u^d. .K*^ ! '^ . I^'u"'? '"^•*' "•"' "*''»•*• »»* k «•» 'h* iui,..r .id. of »he 
 
 poin?!!:iri^»r*"'''"' ^' "^ '"••''''' ■""^''*^ '^"' -■»• «"-; '•».., .,. r,.b«.t ...a 
 
 mo deeply d..p^.«ed ov»l .rei,, oue ou ..ilh.r .id« of the .xUl line of the heml •ei.r.ted 
 from the .urfiace of ,he bon. in front by . well defined t«n.v«rm, rid^e. ' 
 
 Th ■ p«liitine^ PL. »pp,.,r to be in .-outi.t |M).teriorly where they .re .!■>>».» nf .k- 
 
 The tr.„,p»|.tiue. TPL, i. . .troHR. ..un'.Hl bone lying »^.,iuHt the outer ed.,e of th- 
 pterygoid .onnecth,g apparently iu front with .he paKe and IhCiv witj the 
 
 L oMw '7t"'"""r """""'■'"■ °P*""'»« -""^ of the elen,ent. iLtWe'en whio! it it 
 .probable taking mto .on.ideration .« well the . orroborution found in thl ill „f 
 
 ">. ^u Hi- .n the«nXrVp:;.l(U ;^^^i^^^ 
 
 meet in the median line, if they Z.i at alii: extrle." L«bU:.'''Vhtp^ ^1^ 
 supposed prevomerine fragment, in the larg..r skull and the mn, *"" P""'""" "' »•>« 
 bone (ft, in the emalW on^eads to the Sf tha ^ p Utir/ diT^? '""T"' 
 .t wai. of a limited extent. The prevomers were probaWv ;e^rvet^p^ !nd IT T 
 may^have extend«i backward between the intern'al narii T^lli;:!!!;;' Z";:^ 
 
 gmds o. fair sue, embra<i«g the basipterygoid«. extending ba.k to 1" a jZ.i^^'^iah 
 the quadrates, and leaving an interptervKoid varuitv in whi h th . , / T 
 
 iies. Transpalatines narro'w and ^^^^nr^Z:::^:;^^J^;^:^^^;i^ 
 k. and apparently reaching the palatines in front. Palatines LldCa^v't^ u"iUnL" 
 with the perygoids and maxilla-, possibly meeting to a limited extrntTtTe ?„H * 
 line, enclosing, with the transpalatines and the v „Lilla,- IZll. ,^\ • . " 
 
l!» 
 
 MtfititmtHit nj tarftr tkuU, 
 
 RilrmM Wgih irf »|i*<'iilMn (U-ngth <* led rmnus .T* in«h««) 
 
 l>MUa<« \wtmmn mn%M»- .lightly in »ilv«nc« of lli.ir |Mi««iTi<w »wmini»ll<M.. 
 length 111 »atiir» prfurvKil hrt«t<«B m»«ilU *nA jugiil <« Mft tiilo . . 
 
 length iif Mino »muie pmirrtvil <in right •iHe 
 
 M.i»iiiiUMi lirt-wlth (if iM'i't|>ili»i "(ndjfle. . 
 
 Ilitight I'f »«m« rt mill bnwllh 
 
 Width of fofiim»n iiMifnuiii 
 
 Mright of ••iiw 
 
 Hrawlth of Ixuii jKcipiUl 
 
 Thlckii«»« of l»t»rHl Hmige "f •xiHtipil»l • ■ ■ 
 
 tti^ttbio from »rli. uUr f«j« of .Kejpit«l o.iiJyl« to •nUrior end "f p«ri«Ul ridge 
 
 lUiUiiee li«t««>n inner »urf»< -• of »opr»t*i pof»l vMuitim (itppnix ) 
 
 Wl<lth of pitiiiUrjf foramen fnrtii front to h«ck kt mid-length 
 
 I<rnglli o( Kline 
 
 (li'Mitt-t .le, Ih of left r»uiuii (upprox. ) 
 
 length of ilenlsrjr 
 
 Mitximiini ilepth of denurjrul iU mid length (»ppro».) 
 
 Thick m-Mofleft r»mu>>it Miidh.iglit«nU'riorly, twiow liith tooth 
 
 Ijangth of "lUperior bonier of »ur»nguUr 
 
 ThickmtM of «ur»n)»ul»r through th.> riilgi- near ilK uppei border 
 
 Thickneu of NurnnguUr »l«vn the ridg« 
 
 ThicknenH of nuntngular Ix-low the riilge 
 
 Height of Kuranguliir forauirn 
 
 Widtti of »«rap . . 
 
 Width of poxteriiir OTd of aiiguUr 
 
 Widthof name i»t-.,«g, 21 flute VMI 
 
 Thickneiw of "»m« «l wme I>oint 
 
 Tr»n«viTiMi dinmt'ter of »rtiouUri'Otylu« 
 
 Thi.kiies« of r»inuH fnini upper «urf»ce of cotylui. "t iti. mid length, to lower nor 
 
 furr of (leMl»ry _ 
 
 Coiiihinwi thi<:.iir>« of dentiry an.l Hurmigukr (it y. Hg. -'O, pUl« VIII 
 
 length of iTown ..f tifih t<Hith of right ramu. 
 
 ilreiwlth of lift"" of crown of name 
 
 Thickneiw of Iww of crown of Ninii' 
 
 Ixingth of cn.wii of twelfth UKilh of right ramuit 
 
 r«epth of ii.n.r alveolar plat.- of d.ntBry Iwlow Ixlh t«><>th 
 
 Depth of prenpli'iiial below Mnifl tooth 
 
 Ijenjjth of ^plcnial foramen ..... 
 
 Height of name 
 
 DiHtaiicfi lietwcen iiplenial foramina 
 
 Itri'adth of pU'rygoid at its anterior fnd (approx.) . 
 
 Breiiillh of name in advanie of iMxipK^ygoid 
 
 BoMMlth of expo«e.l portiun of pidatiiie a .hort di»tance in advanc- ot it. p.«t4-rior 
 
 end 
 
 Breadth of tran»iwlatine near the front end of pterygoid *" 
 
 Length of hooked process of pterygoid (imperfect at lower end) >° 
 
 MM 
 
 970 
 
 IMA 
 
 u 
 
 M 
 S3 
 
 M. 
 
 M 
 SI 
 
 2JM) 
 
 107 
 
 11 
 
 33 
 
 337 
 
 »on 
 
 IMA 
 53 
 4SH) 
 .13 
 33 
 14 
 38 
 33 
 fiO 
 SO 
 23 
 112 
 
 43 
 10 
 ,'^4 
 1!B 
 IM 
 IS 
 31 
 3U 
 
 37 
 
 »ri 
 
 4.'. 
 85 
 
20 
 
 Tibia and Astbaoai.us. 
 plate ntA'r'aCir £•"''■'• ''•"'•^'''n ''■'"" '' ''" -'-^"1— hewn in 
 
 that th. 'J. bo;.;^ nours:;; w s ^^'^ "•*• ^-"" «""" -<^ ^'^-vs 
 
 an ob,u«.. angle forward^t^l"^^^^ ' ^"^T""^ *"''■'"■*■' ""-""'"y- »'«»<Ji'"r '»^ 
 
 ward. The iSerTeJZttthXZ Z ' "T''''^^''' ^"'^ '"'^'""^•1 "^iqnely h-k- 
 
 is visible in the7ra: tnn^ al";l:f "^ T:r '^^ '"'^''""y ^'***'"'''"» "P '"'» 'he shaft, 
 is shewn, in fig. Tr^Ml'v^S; ZlTL^a^ ^'''"•"""" = " ^^ ""'"^ ^^^''^ *--'-« -'^ 
 
 mid-length, /venly ronndXowar^ '^'^ ? 7'' ""'' ""'*" ''''•''• '""''^"•^ted at it. 
 In front a broad la. m la ,tl '^"h" .-nd, and tern.inating behind in a thin ed^e. 
 
 abends clot"; apX^^ ZZJZZf" 'n"^""!'"" T "'''' *^^' "' Ornmo.,1, 
 part of the prL'J then" nay p^^ Ii; "^ .": t *""«• ^I'tween whi.h and the upper 
 although below the two bo„eL!Iu.> is FwidT r.' ""''""* "' — iA-tion 
 
 oceurs in the lower part of the .«. .n^i. transverse rr^.H^ve ui coneavity 
 
 portion. In this grX a,/d t ;,7;'^^'''^:7;''-.-V'"t"»ti..g its junction with the basal 
 linear depression!. laZpiV^^^^^^^^^^^^^^^^ 
 well defined .one.e area Ir.s the^:!!.!::;;! Z^^r^Z. ^^li^ '■"' ' 
 
 a.traS::;':?;ss^,-:!:::?;h:r^o't" ^^ - ^*'""'"'"'- ^^-"^'-- »-"'-» ^he 
 obii^ie to the tra„i::::e::^ r ie :; 'Thrr o- Jt ^T'-r-v-'---^^ -•■ ">-- 
 
 tibia behind to «o great an extent In O „ /„ fh . ; ' T ' '*°""* "'" "^"''"P ''"' 
 
 Om.l,i„e,| thick,,,.., of tibi,, „,„l ,.t,,„„|„, ,„.„^ „„„,^ _^.,,^. 
 
 "t'r :::-:f ,;'^'-"" — » - ■-- -^^ - o.^. ,;„.. ;.., 
 
 Co„.b,„ed tl.ick.,es« of tibi. ,.n.l astragalus m-ar inner »ide .■■'!■;::;:::,.;;• 
 
 7'i7„Vi. * 
 
 Rreiidtli of distal end 
 
 Br..«dth at fractured upper end of spe..i„,en ' 
 
 MaxruTtti'I"'""" "' ""'™ "' '™'^'"^'^ "PPorend of specimen.' 
 .naximum thieknMs near out(>r side 
 
 Brra,Jth below of obli,,u„ surface of inner Md'e 
 
 Hreadth below of obIi,,ue surfac,. of outer side 
 
 MM. 
 
 102 
 
 7" 
 11!) 
 
 ■ I'art 11 uf ll]i» , 
 
 2tH 
 1.10 
 
 46 
 106 
 
 nil.- |.. .-HI, ti^'. 11. 
 
 igmn 
 
21 
 
 Astrngaliin. 
 
 Breacltli of articular fare : pquals that of .listal eml of tiljia 
 
 KrcaHtli of aHoenHing priMcsa Iwlow 
 
 Btcadlli of sanif where frarturwl alniic (»(>prox.) 
 
 TliickiiPH< of same alwvo, near outer Hide 
 
 TliickiieHs (if sanio almve, near inner »ifle 
 
 Maximum tliickne^s in front of tibia, at outrr siilc 
 
 Maximum thickness in front of tibia, near inner side 
 
 Thickness Ijelow til)ia at outer side 
 
 Thickness liclow tibia at inner side 
 
 HeiKht of facet for calcaneuni 
 
 KnMuUli of facet for calcaneum 
 
 MM. 
 
 •.'48 
 
 I.'. J 
 
 90 
 
 i:i 
 
 :i 
 
 .">r> 
 
 42 
 
 ;i!t 
 
 ;« 
 
 Metataiisai.. 
 
 The metatarsal figured in plate VII nlso noes with the smaller skull ; it is remark- 
 able for its length and slendernes.s and is regarded as the seeond of the right Inub. It is 
 laterally compressed above, has a straight shift and near its lower end is bent .suddenly 
 inward away from Mt. III. The shaft is narrowly rounded in front and flattened on the 
 side that would eome next to Mt. Ill indicating a elo.se approximation of the bones ol the 
 metatarsus to one another. This lat.-ral flat surface is rugose and meets the posterior sur- 
 fa<e which is also rather flat, in a decided angulation that is conspicuously prominent 
 (at a fig 1« plate VII) above the sudden inturu of th." bone below. The proximal arti- 
 cular surfai'e is flat and antero-posteriorly elongated with a length about twi.e the 
 breadth, the distal arti.ular surface is ronnd.'.l and produ-ed well up in front and behind, 
 iH.intin- to a .onsiderable flexibility at this joint. There are well marked vas.ular grooves 
 and pits in both articular surfaces. Externally the distal end is deeply ex.avated. pos- 
 teriorly a shallow groove (''■ fig. 1>^) P"^^-'^ »P«»"1 '■'■'"" the articular sur e : viexved 
 
 from below it is semicircular in outline, flat externally and curved on the inner side On 
 the inner posterior surface of the shaft, b^^low its mid-height, a roughene.l verti.al groove, 
 r marks the position of the distal half of Mt. I, the position of whose lower end is indi- 
 cated by the raised surface at <l. The first digit or hallux would thus be din-ctcd inward 
 and ba-kward in a manner similar to that of the grasping toe of Alhmurus lirst .les- 
 cribed by Osfiorn * in 18!''.1. 
 
 It is probable that the shaft of Mt. I was interrupted at its mid-height. A slight 
 roughening of the surface of Mt. II near its upper end (e, fig. 18) no doubt indicates the 
 position of the proximal half of Mt. 1. The greater i^rtion of one of the tarsal bones 
 remains and is shewn at /. 
 
 Mw-Murenit'iilH of iHffttfarfHiK 
 
 Leni'th 
 
 Antcrofwsterior diameter of upper articular face 
 
 Transverse diameter of mme 
 
 Antero posterior diameter of lower articular face . 
 Transverse diameter of siirae 
 
 MM. 
 
 . .".05 
 
 135 
 60 
 88 
 65 
 
 • llMlletin of the A.M.ru-.n Mu...„ f NutnnU Hi»t..ry. V.,1 .MI. .r.i, I.. X I. PP >M 17-'. ^-O. - Kop. ,o,.l H,„.l l,.,nl,. 
 
 i.f farni\.ir.iu» ami lUrbuuruu« Dinossiiri. fntw. tlie .lurawic "I « >»mmi?. 
 
22 
 
 of thf j;sMolt.\Soft^^^^^ :if r^r r-'*-'- '-- ^^^^ -«» 
 
 bourhood of 30 feet In tht tLI t ' « "**^'y ^ """^ '" ''»^« ''«^n i" the neigh- 
 
 from the muzzle to the t^ oi^ Se t«il I "?. ' '"' ''f ^I" '"'"^"' "»'* *^' '""1 '«'^'h. 
 U«i„g the length ofL^' iTjLlTLZZZSt^^^^^^^ ' '^^ «* T '*"'• 
 
 rnlation. by the rule of proportion, a len Jw 83 f^t i. kV i r "^A^ "' "* '"""'' '^"'" '"'■ 
 similar manner the length of (>J,Zl^«l !/I I* ""^ '^"^ ^ 'W<.««/«,. I„ a 
 
 Richard Owen give* the lenirlh oV mII/ 1" . '^'" """"""'''^ '° ^ ^2 feet. Sir 
 
 of i). a^uilunJ^fZ llSin[^r''T *""*'""'''■ •** »" 3" "^''t ""d Cope that 
 animarmucrmal," Lri>^- 1^^^^^^^^^^^^^ Marsh C,.«, „„„,„,, ^^^ ^,, 
 
 respectively 26 and 38 inches, ;rar„Vme:rCwh;n ^^^^^ '''''-" '^^'^ "«-« 
 
 ofi/L?:Kerf:r"^;:t4^^^^^^^ 
 
 estimated length of 18 inchrftfrth P'° . '"'^ ™°'^'' ♦'^l"^ the mark. Professor Cope's 
 length of the anhnal ""' ""''""*""' ""'"'^ '^"•«" '^''O"* ^O »-t as the total 
 
 Onodal Phalanoks. 
 
 they^aL'tr;^rmi;t^1 JlVsL;T"r f "" f ^Vl"^"''' P"'"''"^- "^'^ -"«- ^ 
 in plate VII ^ ''"P'' *''" '"8^*"* ''"^ »»««* P^'^erved one bein^ figured 
 
 thes/rvt'iTaiJr ;: slirtL:rnurt;r "^!''i '^r °*''^' '-^« --*--• 
 
 rusfrn.nli.in Marsh is nearfy ^ i^.heTC Jht/r* « ''^'" "^^ *»»« '"o* "' ^"— 
 Z). «,«./«„^„.-4 that has a 1^11^0. almost «lch '"" ^'"7' " -rresponding bon. of 
 
 .ip to th. „pp..r edge of the SX r "ur . t Tor^ver.Tin. h" T"'t ''"^ ''"'" ''"■ 
 b<.tweeu the same points) The DhaUnJnfn T ***"'*'« "'""ff the upper curve 
 
 about 41 inches ,„ Tstraight HneC'hMifS'fr''''" ''^^1 '" ^'''"' ""''' '""— 
 along the upper curve) This wo, iT. ^ ^ , ' ^^^"^ *■■"'"'" '"*'*^'" <°^ 4? inches 
 n,uch large! „ pn po ion to .hT^e ^"Z T.^'' T"'*'"' '''''" *" ""■'"'"'»« 
 
 .hc pes, ,hcy do no, apjc r to b' t keep.t Tuh :h '""^'T':' ''"^ '"'''"^-^ '° 
 hind limb. Keeping w,th the size and evident Wrength of the 
 
 poin^i!;';;::^^ij^;.^;;;j;:: z rr ""r'-r-'T '-''-- -'•^'-' ^^-^^y 
 
 plane of the articular facri^ert^alT^^^^ ahnost d.reCIy downward when Ihe 
 
 direction but concavely'Vrved iriitL^ lower surface is slightly, onvex in ,. .raii.verse 
 so as to be angularly rLnd^-dtw S m^^ 
 ;nM.en^h,isaWe^altothema.m2t:d^O::^e?r;:ri:lS;t^ 
 
 • Ii..lletin of th.. Americn M„-«m, of N.tMiml lli.t.,n- Vol XIV . , v„ 
 
 '• ■'■tlivontufrraphical S<<-ietv Mi,ni<m!.h , .til t ■ 
 
 f T™„„<.„„„.of th. An...riin |. il , i : ^J^'1:^^'T"':^'7'^'''-" «"•' '■-'-•< f-natio,.,, ,.«. HI „ o., ,«,„ 
 
 ■IMi 
 
St 
 
 is a roughened transvewe Inberosity, a. of rather small size, lor the attachmeut of the 
 flexor tendon. This tuberosity is separated from the lower border of the articular 8urfa.re 
 by a well defined groove c, that passes upward on each side of the bone and curves for- 
 ward, with greater distinctness, to the tip. Laterally at mid-length, beneath the groove, 
 the bone is expanded ..utward into a prominent ridge, 6, that materially increases the 
 area of the inferior surface. The phalanx, when viewed from above, inclines to the 
 riKht The articular surfa.v is .hallowly concave and has a median groove ducted trom 
 its lower border upward. For a short distance in advance of the sharp edge ol th- arti- 
 cular fa.o the surface of the bone is longitudinally striated and subrugose, elsewhere 
 with the exception of the tuberosity b.'neath, the bone is rather smooth. 
 
 UeamreDumU of iincfiuU plialanx of manu». 
 
 MM. 
 
 Uiatance in a straiRlit line from tip to upper lK^^e of articulnr face 109 
 
 Distance from tip along upper curve to upper erfge of articulnr face l-'i 
 
 Maximum breadth (Ijehind mid length 
 
 Maximum height, from lower surface of posterior tuljer<«ity Ui upper liorder 41 
 
 Height of articular face 
 
 Maximum hreadth of same 
 
 lUlM. 
 
 With the smaller skull was also found part (about half) of the left ilium against 
 which ar.' crushed the neural arches and spines of three sural vertebru-. The neural 
 spines are well .oossitied ; the central one is much greater in its antcr-.-posterior diauieter 
 than Ui • third, and apparently also than the lirst which is imperle.t iu front. The spines 
 are striated above in a vertical direction on their exposed risj^ht lateral surfaces ; they are 
 broken ofl- in a line with the upper border of the ilium. The i.ium its.-lf is broken m 
 front below and b,-hind but inta.t abov. The part represented in thespe.imeu extends 
 from above the acetabulum for some distanc.- ba.kward. It is thin and plate-like present- 
 ing a smooth surface .'xteriorly : it is slightly concave at the centre and develupes a 
 prominent ridge posteriorly below. Beneath the ri.^- the bone is conspicuously excavated, 
 evidently above and in closi^ proximity to the isd.;,.. atta.hment. The lu elabnlar t>or.l.-r 
 is not included in the specim.-n. In iatert'l .ispe, t the upper border has a very slightly 
 arched curve; it is rendered rugose by decided striations directed upward and slightly 
 backward. The portion of the ilium r. maiuing measures :i03 mm. iu height and 870 
 mm. in length. The middle neural spine measures 138 mm., from front to back, near 
 its upper end, and the posterior one !»;■> mm. ; the anterior one is incomplete, .Vefrahsaurus 
 had five co-ossilied sairai vertebra- of which the second, third and fourth neural spines 
 united above. Dryplosaiirus hud at least three, and possibly Hve vertebra', iiuluded in 
 the sacrum. 
 
 Some ofthe . hief points of ditference in the interpretation and enumeration of the 
 elements and openings of the skull oi Dryptosaurm incrassaliis as set forth, in the pr.-li- 
 minary des.ription by Professor Cope in 1892, and iu the present .lescriptiou, may be 
 conveniently summarized, in tabular form, as follows : — 
 
24 
 
 
 ■i.t 
 
 PreHminary deamplinn. 
 
 Orbit. 
 
 PraorbiUl fonroea. 
 
 FronUI. 
 
 Prefrontal. 
 
 Pu«tfront<><>rbital. 
 
 I Epipterygoid. -i- 
 
 I Poatoptic. 
 Urbitosphnnoid. 
 Sur»n«uUr: extend.^ to Imnlcr of articular 
 
 cotylus. 
 Uplenial. 
 Opercular (of Curiei ). 
 
 IViitary + Anjjular in part. 
 
 Angular. 
 
 Articular. 
 
 Articular cotylus: not bifoawte. 
 
 freient tUieri/jlion. 
 
 Pruorbital vacuity. 
 
 Anterior preorbital vacuity. 
 
 Nasal region : naiala iiot recognized. 
 
 Naaal region. 
 
 Prefrontel. (? + lachrymal). 
 
 Palatine. 
 Prevonier. 
 
 Surangular: enters into composition of articu- 
 lar ciitylufi. 
 Presplenial. 
 Spleniul. 
 I*entary. 
 
 In part posterior portion of ilentary. 
 Articular ^- Angular 
 .\rticular cotvlus : liifosfiate. 
 
 Th.'ahovedis.r.-pam7iuth.-d.4.Trainatiouo(the bouo« of th.- skull i>* no douht 
 due to the fiut, that the pn-orbit.-l vacuity was rejrarded as the orbit, l.-adinir to the 
 naming ot a number of the element.s in a,.ordan.e with that idea. Also the --.uoial 
 lately, of th.- matrix in .ertain parts, notably from the arti.ular .otylus and ...,ai thJ 
 inner side of the left ramus in the larger skull, has facilitated the further >tudv of the 
 speeimeus. 
 
 In the preliminary description this species is .hara-terized as differing from Ceralu- 
 suiiru^ nau,,nnis 'in the much larger and more anteriorly placed orbits, and in Ihe much 
 smaller preorbital foramen." 
 
 Ac.ording to the present writer's conclusions the skull of this species differs in a 
 marked degree in certain dire.tions from both that of CeratoM„r„» •> ,a Creomfirus Too 
 httle IS known of the skull ot Mesalo.aurus to allow of a general comparison. In 
 comparing CeratoMuruf with DrvptoMHtm the differences are not to be looked for in the 
 jK«*ltion of the orbit which is pla.ed similarly in both genera, but rather in the size form 
 and disi)osition ol the various bones and Ihe op,-ning8 th-y enclose. Particularly is the 
 variance apparent in the construction of the lower Jaw. As regards the prominent nasal 
 horn .ore ot Cer„t,mur„s, a .orapari.son here fails, as the specimens of DryploMtiru, are 
 deb.ieut in the na«al region. The apparent absence of an anterior preorbital vacuity in 
 fera<o.*«,/r«.vmay be noticed as well as the relative shortness of the dentary bone In 
 />ry/,<,«««r«,,- the iwsi ion ol the foramen, piercing th.- surangular in its hinder part is 
 pe.'uliar; this .jp*.uing is apparently r.preseut..d, in the jaw of Cerulomur«f. by the larger 
 and more anteriorly i.la.-.d loram..|i in a position similar to that of the external m„H,libular 
 foramen ot th.- cro.odile. There an- reasouabl.. irrounds for supposinir that there w.-re 
 twe ve l.eth lu th.- maxilla of Driptosanrus <is . oinpar.'d with lift..eii in Ceralosauru, also 
 the low..r jaw is larger, in .omparison with the rest of the skull, in the former spe,ies 
 than in the latter. ' 
 
 \nCreosaur«s there ar.. ihr.H. pn^orbital vacuities, two pla,,.d as in Drv/Xosuuruo and 
 an ad.litionalon.of.siual! sizebelw.-en the pn-niaxilia and the maxilla The skull is 
 higher, in proportion to the length, than in D. imrassaln:, but in the att.'mpt.'d r.'st..ratioii 
 of the skull dig. A p. 2,".) of the (;ret*..,.us spe. ies it is possible that sulh.i..nt allowan.e 
 
25 
 
 ha* not been made for the criuhing from above to which the 8i>e<imenB have boen subjected. 
 So far UB a comparison can be carried out the ireneral dispOHition of the diHerent elements 
 are remarkably similar but when examined in detail the ,.roiK>rtion8 of the bones and 
 their enclosed foss!.- are ditferent throughout resulting in the Cretaceous type in a more 
 depressed form of skull. 
 
 ^iiililiiMlr.l^''^ 
 
 \> 
 
 ^ 
 
 \J 
 
 
 K,,.. .\. K.,.„r»t, f ,h.. .kull ..f l,r,„ ,. ,„..,..„<„.: l,.f. I.t-r.: ..,..-t : d- ">.-. .n- -l..l..!y .„..r,. ,hun , 
 
 .illlit. 111.- ii;itiiti\l -m: Tlii-.I..Util liii.»in.luiili'lliir.»t..n.il |«it«. 
 
 \ I \ i 
 
 
 ^ 
 
 ~ v___ i.^'^ 
 
 I'll,, l^. [HUfT 
 
 i.« of till. I.'t ramus .villi tli.' oirnMnicI :in:l 111.- aiiti-ii.ir iiui ..f tlir angular r.-»l..i-^-.l. 
 
f 
 
 I J 1! 
 
S7 
 
 BlBLIOdUAPUY. 
 
 189' Cope E. D. On the .kull of M.e dino^urian Map, i,ura,mtu,, Cope. Proceeding- of the 
 American Philoiophioal Mociety, vol. X.\X, p. 240. 
 
 1^90 Cope, E.D. On the homologie. of the ,-«terior cranial arche. in th../f.p<.«a. Tranwction. of 
 1^9-. t.ope, ^^^ ^^^^^^^ Philc«„phical 8,«iety, Philadelphia, vol. XVII, n«w «>neH, p. 17. 
 
 1899 Hay O. P. On the nomenclatun. of certain American fo«il vertebrate.. American OeoIogUt. 
 vol. XXIV. p. 346. 
 
 190^ O,born. H. F. and Umbe, U M. Contributions t.. Canadian Pal«<.nU.logy, vol. Ill (,,u.rto), pt. 
 190-. U«born.n ^^ On Vertel.raU of the Mid CreUceouB of the Northwest Ternary, pp 
 
 IK and 27. (1) Distinctive characters of the Mid Cretaceous fauna by H. 
 V. Ohborn. (2) New genera and species from the Belly river series (Mid 
 Cretaceous) by h. M. Lambe. 
 1903. Umbe, L. M. On the lower jaw of DrypU«aurus incrassatus (Cope). Ottawa Naturalist, vol. 
 XVII, p. 134, plat«s I, II ami III. 
 
ii I f 
 
PLATE I. 
 
t 'I 
 
 PLATE r. 
 
 Dryplomtirui inerauatus (Cope). 
 
 fig. I. iikull of iDMllpr •peciineD, Hoperior view ; on« thin] natural siw. P,gf 8. 
 
 APV «,t,Tior preorbital v^-uity : IN, inU.rn.1 n.r« ; J, jugal ; I, lachrym.l ; M. maiilU 
 O, orbit ; PK. prefronUI ; PM, preniMill., ; PM8, premaxillo-in.xilUry sutur* POB 
 pMtorbiUl Ur ; PV. preorbital vacuity ; 8(.V, .urborbiul »«:uity ; a, ,K).U,rior l»rder of 
 poatorbital Iwr ; 6, prevoiner ; c + (f, palatine. 
 
 l> i 
 
 i it 
 
< 
 -I 
 
 a. 
 
 naxilU ; 
 ; HOB, 
 order of 
 
 
 
 
I! f 
 
 
PLA TK IT. 
 

 PLATE 11. 
 
 If 
 
 FiK. 
 
 DryptomHrun inrrtunalug (Cope). 
 
 Skull of sinallp. specimon, lateral view, seen from tl... left ; one-third .mtur,il s„.e. Page 8. 
 
 APV, anterior preorbital vacuity ; IN, internal nan-s ; J, ju,.al ; I, lachrymal ; M, maxilla ; O, 
 orl.it; I|., prefrontal; Pf)H, p.»torl,ital l.ar ; PV, preorhital varuity ; S(»V suU.rbitol 
 vacuity ; n. posterior l«r.ler of |K«t.>rl.iti,l Ur ; I., prevomcr ; r + </, palatine 
 
 iif 
 
 .>! 
 
 
 111 
 
 tX^Si.-^ 
 
< 
 
 a. 
 
 Page 8. = 
 
 O 
 
 O 
 
J I 
 
 n 
 
 MJ 
 
l^T.A^n: HI 
 
s ! 
 
 PLATE Iir. 
 
 DryptomuriiH incnumtu) (Cop«). 
 
 
 ii 
 
 *•""" ' • — — «»g|n 
 
iwing 
 
 iiiiil : 
 'loiid 
 
 < 
 2: 
 < 
 
 > 
 
 "•J 
 o 
 
 o 
 
m 
 
 •^ 
 
 u 
 
 ill 
 
 I' * 
 
 i j i 
 
 it 
 
 M 
 
PLA.TK IV. 
 
I'l-ATK IV. 
 
 ..i«...., ,L. ..... ;:: z:;: „:::;' :;:7: "ir^"" """ ■"""' ""■« '^-- "^--"^. ">•• 
 
 P "U ;"PV "";^r •"■"'""'■ ''■••'•«'"""- f*^. vomer (p.„.p,.,.„„i,„; PS, 
 
 u, ..... uf ...sht .upnu..„,p,„..l V. „„y ; X, .uture l«tw..„ „„..il „J ,„,„, „ ,„, 
 
 tiK.ili ; * p,jHii,uu ..f piluilaiy funimeii. ' 
 
-J 
 
 a. 
 
 lit 
 
 SI 
 
 
 > 
 
 u 
 
 e; 
 o 
 _j 
 o 
 
 UJ 
 
pj.A'n: V. 
 
HLATK V. 
 
 /hii/ilimiiKniH iticrtitnatiiM (Copf). 
 
 Kit,', .'i. Skull «>f lnrKiT xinwiiiii'ii , mniiili>ili', mvh frmii th<' lift, lvlii({ Imneikth the crnniuiii, nhdwiiiH thi' 
 Bxteriiir surface of the left rHiiiun ami tin- interior surfmv wf tiio rii;ht riiiius. K.jur tlfli'Ciith', iir 
 ■iJKhtly iii'iri' llmii uin' fourth, mitural »i/c. Vnge 12. 
 
 AN. aiiKulnr . A li, articular. HT, li;isi|>t«r>«iii(l , l>, .Icnlnry ; l>l'. iririf>r alvc.iliir jiliitc .if 
 ilciit'iry , K'>, px.)c,i|,iial : .1, jUKal ; M, maxilla: I'l., palatini-; I'SI', |in'Hjilfnial ; I'T, 
 ptcrji{iiiil . i;, .|uailrali' ; SA, ^unlen{ular ; .SuV. nuiwirliilal vacuity , ST, ^plcnial ; TIM,, 
 trannpalalinc ; /, anterinr uiarj-in of ( spcnnil splciiml furamcii ; It, suture Lelsu'wii iimxilla 
 ami junal . in, twelfth to.iih; ii, maxillary toiilh with sucic>.>.iiiiial t<nith atmve : IIS. 
 UuiiMphunoiil. 
 
 H 
 
 ! 
 
PLA.TE \'I. 
 
 •-■-M m mm u W 
 
 Itg^g^gmmmmm 
 
PLATK VI. 
 
 FiK. 
 KiS. 
 
 FiR. 
 
 Kiij. 
 Kij.. 
 
 Ki,' 
 
 DryptoMurnn inemamlut (Ci>[)e). , 
 
 6 The M ™K.>l.i» enilnarinK tl.e disUl .-.ul of the riRl.t tibi« an.l shewinK tW asoen.linB pivKr^ : 
 anU-rior view. One half n,.ti.n.l si/e. ColU-cwl will, the smallT skull. P-W -.iO. 
 
 7. Posterior i i.-w of the sum.' : one half nnturiil size, 
 
 H. I>'ft Uteial a-iiifct of the siHiie ; one half natunvl si/*. 
 
 ;.. Kxtenial lateral a^,-.t of .-rown of t..,th, . olloct^l with the sni^ll-r skull, natural size, with a 
 few of the ilenticles enlarijeil four times. I'nfi''- 1 1 antl 17. 
 
 10. Outline of transverse »e.tio„ of same t«..th, at al-mt ono-thinl the height of the .mwu l-'low 
 the a|iex ; natural si/e 
 
 11. Outline of transverse section of «une Us.th at a litll.. l«;low the mi,! l.e.^hl. of the crown ; 
 natural size. 
 
 l-> Outline of tr-msverse section of -«.n,e t.K.th, r.ear the l«i.se of the crown ; n.-.tural size. In the 
 
 ..utlines of tions, shewn in liRS. 10, 1 1 an.l VI. the upper side corres,M.n.ls to the outer surface of 
 
 the t<H,th and the end to the ri^l.t to the ant..ri..r Is-nler of the crown 
 
 13. .\nterior view of crown of same tisith ; n.-itural .size, 
 
 14. Posterior view of crown of same tooth ; natural size. 
 
 A, astragalus ; AS, ascendiiix process of astraRalus ; T, tibia 
 
GEOLOGICAL SURVEY OF CANADA 
 
 PLATE VI. 
 
 ^ti.'O-'yt CO 
 
 I. M uAMIf. DIIT. 
 
 ■'-^'^^^p 
 
PLATE VII. 
 
PLATE VII. 
 
 Dryptoaaurus tii<-ni»«i/"» (<'')p<-). 
 
 Fig. 15. Occiput of Urger ,kull, posterior view, shewing the occipital condyle and foramin. ; one-half 
 
 the natural size. Page 1 -V 
 Fig. Iti. Ungual phalanx of niauus ; foun I with the smaller skull. Natural si/e. Page ^2. 
 Fig. 17. The same phalanx, viewed from l^^hind, shewing the articular face ; natural siie. 
 Fig. 18. MetaUrsal II of ri^l.t li.n!. ; 1-ft lateral aspect obliMUely from behind. One-third natural size. 
 
 Found with the smaller -^kull PiiU" 21. 
 Fig. 19. Distal end of left quadrate of larger skull ; anlerio- view. On-half natur.M si/.e. Page 17. 
 HO, Usi-oecipital ; CF, oan.tid f"ra«,en ; EO, ex-wcipital ; FM, foramen magnum ; OC, occipital 
 ■ condyle ; X, M, XII, exits of cranial nerve». 
 
GEOLOGICAL SURVEY OF CANADA 
 
 PLATE VII 
 
 '■ — -~r 
 
 iV 
 
 . H lAMIF. 
 
 H(LOT**t CO. 
 
PLATE VITT. 
 
PI,.\TK Vllt. 
 
 l>i)/iAomiirii» iuenumliit (Cope) 
 
 Fig. 20. Exterior Mpect of posterior end of left ramus of Urgir akull ; .ne-half natural nir. Page 1 4. 
 Fig. 21. Interior view of tl'.e same ; similarly reduced. 
 
 Fig. 22. Pituitary foramen, as seen in larger upeciinen, from Iwlow ; natural size. Page 14. 
 PN, pituitary foramen ; HI. exit of oculomotor nerve ; *, keel ; o, anterior end. 
 
 1^ 
 
GEOLOGICAL SURVEY 0^ CANADA 
 
 PLATE V 
 
 . M iAHM. DELT. 
 
 NHOTvaf CO