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( APR 1 9 1935 


McCalla & Stavely, Printers, 237-9 Dock Street. 

Auojust, 1869. 






Head September 18, 1868, and April 2, 1869. 


It is not designed in the present essay, to give descriptions of the known remains of 
the Batrachia, Reptiles and Birds, which have been more or less fully made known by 
others. This is left for the day when our knowledge shall more nearly approach complete- 
ness. While the subject is in its infancy, I have thought best to describe only those 
species and types which are new, and those portions of imperfectly known forms which 
will throw additional light on their relations and affinities. In adhering to this plan, I 
have been able to add no little to the history of the Reptiles already described by my 
predecessors, Leidy, Owen, Dawson, Wyman, Lea, etc. Where, however, I have had 
nothing to add, I have referred to their published descriptions, which are numerous and 
well-known. The literature of the subject will then be found under the respective specific 

The present Memoir was originally prepared under the title of " Contributions to the 
History of the Vertebrates of the Mesozoic Periods in New Jersey and Pennsylvania," 
and presented to the Academy of Natural Sciences of Philadelphia, for publication, Fifth 
Month, 14, 1867. The more important parts of its contents were at the same time 
embodied in a series of remarks before the Academy. This essay was withdrawn, owing 
to delay in the publication, and the remarks "made were not printed. An abstract of part 



of them was, however, piiblished in the Proceedings of the Academy for the same year, 
page 234. 

Additional material was shortly afterwards sent to the writer, and the important con- 
tributions on the Batrachia of the coal measures, and on the Elasmosaurida?, written. 
The Palaeophis and some of the Testudinata and Pythonomorpha were also added. 

In the course of these investigations, prosecuted during the past six years, with 
reference to the structure and relations of the extinct Peptilia, the following general con- 
clusions have been attained to, besides many of lesser significance. 

First : That the Dinosauria present a graduated series of approximations to the birds, 
and possess some peculiarities in common with that class, standing between it and the 

Second : That serpents exist in the Eocene formations of this Country. 

Third : That the Chelydra type was greatly developed during the American Cretaceous, 
and that all the supposed marine turtles described from it, are really of the first named 

Fourth : That the Peptilia of the American Triassic are of the Belodon type. 

Fifth : The discovery of the characters of the order Pythonomorpha. 

Sixth The development of the characters of numerous members of the Batrachian 
Sub-order Microsauria in the United States. 

1 must express my obligations to Prof. Geo. H. Cook, of the Geological Survey of 
New Jersey, who kindly placed the specimens procured during the Survey at my disposal. 
I am also particularly indebted to Prof. John S. Newberry, of Columbia College, New 
York, and director of the Geological Survey of Ohio, for the loan of the unique and 
important material from the carboniferous beds at Linton, Ohio, contained in his private 
collection. I am under similar obligations to Wm. P. Webb, Superintendent of the Land 
Office at Topeka, Kansas, for the important type specimens of Polycotylus latipinnis, 
and to Prof. Agassiz, for the freedom of study and description of the unequalled Mosa- 
sauroid material in the Museum of Comparative Zoology, Cambridge. Also to Philip P. 
Tyson, of Baltimore, for similar advantages, and to Dr. Theophilus M. Turner, of Fort 
Wallace, Kansas, for the discovery of that extraordinary reptile, the Elasmosarus pla- 
tyurus, and its shipment in unusually good condition. Dr. E. P. Showalter. of Uniontown, 
Alabama, has placed me under obligation, in sending the beautiful fossil of Clidastes 
propython. I must also express obligations to Prof Marsh, of Yale College, Dr. Lock- 
wood, of Keyport, New Jersey, and to other friends. 



The Classes Aves, Reptilia, and Batrachia are those over which the present review 
extends. The classes of veretebrata not included are : the Dipnoi, Pisces, Elasmobranchi, 
Dermopteri, and Leptocardii and the Mammalia. 

The Aves, Reptilia, and Batrachia are characterized and distinguished from all the 
other classes as follows : the points wherein they differ from each other are italicized. 


Axial element of the brain chamber a single membrane bone, the parasphenoid ; occipital 

condyles two, on the exoccipitals. 
Mandible compound, supported by quadratum. 
A distinct coracoid bone. 
Limbs when present ambulatory, attached anteriorly to a scapular arch which is free from 

the cranium. 
Xervous System. Cerebral hemispheres larger than optic lobes, not covering the optic 

thalami, and with the lateral ventricle on their inner side. 
Fornix and arbor vita? none; medxdla oblongata straight ; olfactory lobes terminal, sessile. 
Circulatory System. Heart with two and three chambers. 
Three or more aorta bows; aorta with two roots from a ductus communis and bidbus 



Axis of brain case, the basi-occipital and sphenoid elements developed in the primordial 

cartilage, the first with exoccipitals bearing one condyle. 
Mandible compound, supported by quadratum. 
Coracoid bone distinct. 

Limbs the anterior attached to a scapular arch which is free from cranium. 
Metatarsals and metacarpals distinct; carpals and second row of tarsals also distinct; 

usually the first row of tarsals also. 
Pubis not in contact with iscliia distally. 


Nervous System. Cerebral hemispheres larger than optic lobes, extending over and con- 
cealing optic thalami, and with the lateral ventricles on their order side. 

Fornix and arbor vita? none ; medulla oblongata abruptly curved ; olfactory lobes terminal 

Circulatory System. Heart with three or four chambers. 

Aorta ivitli two roots, and rarely an additional bow ; no bulbiis arteriosus. 


Osseous structure as in Reptilia, except metatarsal and usually metacarpal bones are con- 
fluent Avith each other, and with the carpal and second series of tarsal bones ; first series 
of tarsals confluent with tibia. 

Pubis turned backwards and more or less confluent with ischium. 

Nervous System. Cerebral hemispheres larger than optic lobes, and concealing optic 
thalami with the lateral ventricle. 

Fornix and arbor vitce present ; medulla oblongata bent; olfactory lobes inferior sessile. 

Circulatory System. Heart with four chambers. 

Aorta with one root turning to the right, no bows, and no bidbus arteriosus. 

Class I.-B^lTR^CHI^. 

The vomer is double, and usually bears teeth in this class; the premaxillary is single 
or double* Teeth never planted in deep alveoli. 
There are six orders, as follows: 


Caudal vertebra; and frontal bones distinct. Inferior pelvic elements not confluent. 
O. o. maxillaria, prefrontalia, palatina and pterygoidea wanting; nasalia present. 
Ethmoid, two lateral pieces, each forming part of palate. 

Mandible toothless, condyloid, teeth pleurodont. No "postorbital and supertemporal 
bones." First pair ceratohyals distinct. 

* Two premaxillary bones are usually ascribed to the Batrachia, but in many Salamanders they are confluent. 
Thus while they are double in Salamandra, they are single in Hemisalamandra, Triton and Diemyctylus. In 
Amblystomidaj they are double. Among Plethodontidai, they vary. Of Plethodontine genera Batrachoseps and 
Stereochila (Cope gen. nov. for Pseudotriion marginatum Hallow) have them single, and Plethodon double. Of 
Spelerpine forms, Manculus (Cope gen. nov. for Salamandra quadridigitata Holbr.) Oedipus and Spelerpes have but 
one, and Geotriton and Gyrinophilus (Cope gen. nov. for Salamandra salmonea Storer Pseudotriton salmoneus Bd.) 
have two premaxillaries. Desmognathus and Amphiuma have single premaxillaries. 



Caudal vertebra? and frontal bones distinct. Inferior pelvic elements not confluent, 

O. o. maxillaria, prefrontalia and nasalia wanting; palatina and pterygoidea present. 

Ethmoid* a vertical plate on each side the cerebral lobes. 

Mandible toothed, teeth plcurodont. Ceratohyals, first pair connate. 

Xo " postorbital and supertemporal bones." 


Usual cranial bones present, but pterygoids reduced or wanting. 

No "postorbital or supertemporal bones." 

Caudal vertebra? and frontal bones distinct. 

Ethmoid, a vertical plate on each side. 

Mandible dentigerous ; teeth pleurodont. 

Inferior pelvic elements horizontal, in contact; no osseous pubis; ilium suspended to a 

sacral rib. 
(Mostly no quadratojugal.) 


Usual cranial bones present and distinct, including frontals and pterygoids. 

Caudal vertebrae distinct, 

Xo "postorbital or supertemporal bones. "f 

Ethmoid annulus surrounding cerebral lobes. 

Mandible dentigerous ; teeth anchylosed by their bases. J 

(A quadratojugal.) 

* Erroneously called orbitosphenoids by me. Journal Acad. 1866, (on Anura.) 

f When the temporal fossa is overarched, it is by expansion of the maxillary and quadratojugal. (Stannius says. 
"Squama temporalis.") 

X The teeth of Csecilia are compressed with a trenchant posterior edge, which is crenate after the manner of 
Megalosaurus, Carcharias, etc. Thus to the numerous genera of Sanrians and Selachians possessing this character, 
must be added a Batrachian. 




Usual cranial elements distinct, including frontals and pterygoids, and adding "postor- 

bitals and supertemporals." 
Caudal vertebra;'? 
Orbitosphenoids normal. 
Inferior pelvic elements distinct. 

Mandible dentigerous; teeth with anchylosed bases, or in shallow alveoli. 
Ethmoid. % 
(A quadratojugal.) 


Frontal and parietal confluent, nasals wanting or rudimental; other cranial bones present. 
Postorbital, supratemporal, and usually nasals wanting. 
Ethmoid an annulus (usually complete above) surrounding cerebral lobes. 
Caudal vertebra; represented by an elongate compound style. 

Inferior elements of the pelvis consolidated into a single vertical mass; ilium attached 
immediately to sacral vertebra?. 



The vertebral centra not ossified; the teeth simple; no branchial hyal bones; occipital 


Vertebral centra 'ossified; no branchial hyoids; teeth simple or with slightly inflected 
enamel of the basis; occipital condyles. 


Vertebral centra cartilaginous; branchial hyoids present; teeth with inflected enamel, 
anchylosed by their bases. No ossified occipital condyles. 



Vertebral centra osseous; no branchial hyoids; teeth with much inflected enamel, 
anchylosed in shallow alveoli. Occipital condyles. 
Our knowledge of these forms is as yet in many cases too incomplete, to enable us to 
assert positively as to the structure and position of the teeth, and the preceding arrange- 
ment is designed to shadow out the true system, rather than to define the groups exactly. 
They may be arranged further in the following manner, with reference to the dermal 

I. Three large pectoral plates. 

« Abdomen with numerous short or long bony scales in close series. 
P A bony sclerotic ring. 
Teeth simple. Xenorhachia. Amphibamus. 

Teeth complex. Ganocephala. Archegosaurus. 

PP Xo bony ring. 

Colosteus n. gen. 
Microsauria. Ceraterpeton. 


II. Xo pectoral osseous shields. 

a Abdomen with oblique series of long or short scales. 

Microsauria. Sauropleura. 


aa Xo abdominal scales known. 



This order I proposed for the reception of the genus Amphibamus Cope, in 1865. I 
proposed to regard as one of its characters, the existence of opisthoccelian vertebra?. Such 
impressions were observed in the matrix in which the fossil was preserved, as to induce a 


belief in the existence of such vertebrae, and the existence of these in a well ossified con- 
dition, in the apparently nearly allied genus Raniceps Wyman strengthened such belief. 
There were actually, however, only osseous neural arches present, and I am now decidedly 
of the opinion that the vertebral centra were either cartilaginous or annulilbrm, as in 

Proc. Acad. Nat. Sci. Philadelphia, 18C5. 134. 


Prop. Acad. Nat. Sci. Philadelphia, I860, 134. Palsentology, 111. State Survey, Tab. 
Carboniferous ; Lower Coal Measures ; Morris County, Illinois. 


This suborder was established by Prof. Dawson for small lizard-like vertebrates from 
the Coal Measures, which he thought presented points of affinity to the Saurium reptiles, 
at the same time recognizing Batrachian characteristics. 

These creatures form, in fact, a series closely resembling or parallel with what was 
probably an immature stage of the Labyrinthoclontia. They are, Labyrinthodonts, 
with simple, or very slightly inflected enamel of the teeth, and with the extent of the 
exostosis of the cranial bones much reduced. This character has been much overrated 
by some authors. In the Dendrerpeton obtusum Cope the grooving and pitting exists 
only on the posterior parts of the cranium, and gradually disappears anteriorly. In the 
Alligator mississippiensis the same is the case. 

The only species, included in this tribe, in which inflections of the enamel have been 
described is the Dendrerpeton acadianum, and here it is only at the base of the tooth. 
It is, however, not impossible that this genus should not be associated with Hylerpeton, 
(Estocephalus, etc. 

The genera Urocordylus, Ceraterpeton, Lcpterpeton, Ophiderpeton, and others 
recently described by Prof. Huxley, also belong here. 

The genus Brachydectes m. is established on portions of the crania only, while 
Sauropleura m. is known from portions of all the skeleton except the cranium. There is, 
therefore, a possibility of a double emploi in this case, though not in respect to the 


P ELI ON, Wyman. 

Proc. Acad. Natl. Sci. Philadelphia, 1868, p. 211. Raniceps, "Wyman Amer. Journal Sci. and Arts, 1858, p. 158. 
Not of Cuvier, (Pediculati.) 

PELION LYELLII, Wyman. Raniceps lyeelii, Wyman, I. c. 

This animal differs from the genus Amphibamus, in the well ossified vertebral axis; 
no remains of a tail with elevated neural spines exist in the type specimen, nor have 
ventral scales or sclerotic bones been seen. 

Middle Coal Measures, Jefferson county, Eastern Ohio. 


This genus embraces the smallest species of the order. They all pertain to that 
interesting Batrachian fauma of the Coal Measures of the Joggins of Nova Scotia, eluci- 
dated chiefly through the exertions of Principal Dawson, of Montreal. This fauma 
embraces six of the Microsauria and one true Labyrinthodont. Of the former, the 
Hylerpeton dawsonii Owen, is the largest species, the Dendropetons next, and the 
Hylonomus wymanii is the smallest. As Dr. Dawson has described these curious 
animals in the " Canadian Naturalist," in detail, I will not repeat them here, but add a 
list expressing some peculiarities of dentition, which are highly important in the deter- 
mination of species. This, giving the number of teeth in a line of 1-1 2th of an inch, has 
been furnished me by Prof. Dawson. 

Loo. Cit. VIIL, 167, Coal Measures of Nova Scotia. 

Loc. Cit. VIIL, 258, Coal Measures; with the last. 


Loc. Cit. VIIL, 270, Coal Measures ; with the last. 

2Fo. of Teefli in Line. 
Dendrerpeton acadiannm. 

Outer series of teeth, 4 teeth in one line to lj line. 

Inner do. 4 in 2i lines. 
I), owenii. 

Outer Series, 4 in one line. 

Inner do. 4 in two to 2| lines. 

Hylerpeton dawsonii, 4 in five Hues. 

Hylonomus lyelli, 12 in two lines. 

H. wymanii, 12 in H lines. 



Proceed. Acad. Nat. Sci. 18G8, p. 211. 

This genus is represented by a large part of the cranium of a batrachian from the 
triassic coal measures of Chatham county, North Carolina. If not a batrachian, it could 
only belong to a Ganoid fish, but though some of its characters are somewhat ichthyic, it 
lacks the following important elements of the Ganoid structure, *. e. post and suborbital 
bones; postnareal cavities, branchiostegal, and arched branchihyal bones. On the other 
hand it has a large preorbital, bounding the frontal and maxillary to the nares, and the 
inner border of the orbit, as in Stegocephalous Batrachia; also a postorbital element, 
contributing to the formation of an extended supratemporal roof. 

Contrary to what has been found the case in most genera of Stegocephali, the 
maxillary appears to extend posteriorly to a free termination, as in modern Salamanders, 
and the supratemporal* bone presents a very prominent, obtuse, arched margin. This 
margin extends from the orbits on each side, and is inclined towards the posterior part of 
the cranium. There is therefore no quadratojugal piece. 

The maxillary and mandibular pieces are slender, flat bones, as in Menopoma; the 
form of the posterior or articular portion of the latter cannot be ascertained from the 
specimen. The more or less exposed part of the median region of the latter, exhibits a 
succession of shallow transverse notches, enclosing thirteen obtuse elevations. The 
former resemble rudimental lateral alveolae for minute pleurodont teeth. A few other 
similar minute ribs, and, perhaps, a minute curved cone without sculpture, are the only 
other indications of dentition. 

The bones of the upper surface of the cranium are more readily interpreted by 
reference to those of Menopoma. A pair of narrow nasals, acuminate behind, penetrate 
between the frontals as for posteriorly as the posterior margins of the orbits. The suture 
between these is very distinct, and entirely straight. The preorbitals extend to above 
the orbit, and then appear to cease with a transverse suture. Between these and the 
nasals a broad triangular element enters on each side, not attaining the probable position 
of the nostrils. Each is divided by a longitudinal groove, which is probably a suture, and 
which woidd then divide the frontals from the parietals. The frontal would then divide 
the parietals entirely, as they do in Menopoma, for the anterior half of their length. This 
would give the frontals a narrow form, acuminate in front, and bounded behind by a 
regular coarse, zig-zag transverse suture. The cranium behind this point is rugose, and 
the surface not well preserved, and it can only be said, that two peculiar grooves converge 
to a point between the posterior extremities of the frontals, like the boundaries of the 
supraoccipitals. The posterior boundary of the cranium with the condyles cannot be 


readily determined. "When the postorbital roof bone is raised up, the meeting of two 
gular dermal bones, as I interpret them, is seen. One of these is a plate directed 
backwards and outwards, bearing minute radiating lines on its upper surface. It meets a 
similar flat plate directed forwards and outwards with similar lines radiating to the 
circumference. The inner margins of these plates were not seen. 

The orbits are remarkably small, and situated probably near the middle of the 
longitudinal measurement of the cranium. The external nares are not defined, but 
symmetrical depressions in the position they usually occupy in Salamanders are distinct. 

The general form recalls Menopoma, particularly the small orbits. A slender curved 
bone with a slightly dilated and truncate extremity, lying by the cranium in connection 
with the mandible, is like a branchihyal of that genus. Nevertheless it cannot be 
positively assigned to that genus, as numerous cycloid scales of fishes are on the same 


The surfaces of the cranial bones are little sculptured ; there are small tuberculiform elevations on the parietal 
and more numerous oues on the preorbitals. The postorbitals show the strongest markings of elongated pits, which 
radiate to their circumference, leaving a smooth obtuse border. The nasals present a series of small warts at a little 
distance on each side of their common suture, and transverse to it. The surface of the maxillary is marked with 
longitudinal grooves and shallow pits. 

Kb suture separating niaxillaries and premaxillaries can be traced with certainty, though the bones of the jaw 
are interrupted at the usual place of suture, opposite the nostril. 

Measurements. _ Lines. 

Length of specimen (including mandible), 18 

Width between outer convexities postorbitals, 17 

Do. do. inner borders orbit, 11 

Do. of same without preorbitals, 8 

Do. of nasals at middle, 2.5 

Do. of orbit, 1.5 

Length of frontal and nasal premaxillary, 11 

Do. of supposed branchihyal, 12 

The name is derived from the roof-like postorbitals with free lateral margin. 

Locality. — Coal bed of the Keuper Triassic, Chatham county, North Carolina. The 
species was discovered by Prof. Jos. Leidy, who handed it to me for description. It is in 
the Museum of the Academy Nat. Sciences of this city. 



Journal Geological Society, London, 1853, p. 81. 

Iii the form of the cranium this genus differs from Brachydectes and cestocephalus 
much as M enoponife does from Amphiuma. Two species appear to have left their remains 
in the coal measures at Linton, Ohio. 

There is an internal as well as an external suries of maxillary teeth in this genus, and 
a vomerine patch, according to Dawson. The skin was ornamented with osseous scales 
of an oval form, some of which were longer than others, and formed crest-like series along 
the side. In a specimen of the mandible of the D. acadianum, kindly sent me by Prof. 
Dawson, the inflection of enamel at the base of the tooth is readily observed, but it appears 
to be as smooth as. in any other type of the Microsauria above the alveolar margin. 

Fig. 1. 


This species is known by a partially preserved cranium. The 
superior surface is exposed, the outlines of the jaws and orbits are 
well preserved, with the occipital condyles. The os quadratum is 
directed obliquely backwards, and the angle of the mandible extends 
to a line a little behind that of the occipital condyles. The 
zygomatic arch exists in a position similar to that in which it may 
be seen in a few genera of Anura, as Discoglossus and Pelobates. 
It extends downwards and forwards from the supra-squamosal to the 
maxillary region, but whether it is homologically squamosal or 
malar the specimen cannot show. The postorbital is present as 
well, and with the last, and the supratemporal, forms the bony roof 
of the temporal fossa. A piece which may be the pre and post 
frontals combined, borders the inner superior margin of the orbit, it 
■widens posteriorly, where it has contact with the parietal, etc., and 
narrows in front. Supraoccipitals form together a broad triangle 
on the upper plane of the cranium, of less extent than the adjoining 
supratemporal. These elements are pitted, and towards their 
margins radiate grooved. These sculpturings grow less on the 
margins of the supratemporal, and the portions of the surface of the more anterior elements remaining, are so slightly 
marked as to give the impression that the sculpturing in this speeies is much less than in others of the genus. A few 
beaded ridges are all that remain on the parietals and postorbitals ; the maxillaries have a slightly stronger sculpture 
seen in a few spots. 

The general form of skull is elongate behind, and much shortened in front of the orbits. The orbits are thus 
altogether in front of a line equally dividing the cranium transversely, while in the D. acadianum they are in the 
middle of the skull. The outline of the muzzle in our- species is then broad, rounded, as in the Menopoma alle- 
gheniensis, while in the latter it is ovate and produced. It therefore resembles also in its proportions the genus 
Herpetocephalus Huxl, from the Irish Coal Measures. 

The parietal bones extend to opposite the posterior margins of the orbits, are then gradually contracted, and 
form an acuminate prolongation on each side the wedge-shaped frontals. The prefrontals are thickened on each side 
the front, behind the external nares. The sutures defining the frontals anteriorly, the nasals, and the premaxillaries 
behind cannot be made out. The median longitudinal suture is a marked and zigzag one, and can be seen as far 


posteriorly as the anterior margin of the orbits. The external nostrils are large and opposite the inner margin of 
the orbit on each side. This separation of the nares is associated with a greater transverse extent of the x'remaxil- 
laries than in some of the genera. These have been set with numerous teeth, judging by their small impressions ; 
no larger ones have left traces, and no traces of any on the maxillaries. The teeth of the genera before described 
are all much larger relatively, indicating still further the diversity between them. 

A fragment of mandible remains, but without teeth or external surface. It shows a large internal canal. 

Measurements. Lines. 

Total length cranium, 25.5 

Width do. three lines behind orbits, 24 
Do. between orbits, 7.5 

Do. do. nares, 5 

Do. occipital condyles, 2.2 

Do. of supraoccipital bones, 6 

Do. of right parietal, C 

Extent of premaxillaries, 8.7 

Length orbit, 6 

From the Coal Measures at Linton, Columbiana county, Ohio. Discovered by Dr. 
Jno. S. Newberry. When the remainder of the skeleton of this species is known, its 
generic relations will be better established. 

Another cranium accompanies the collection, which belongs to a species distinct from 
the last. The muzzle is not so broadly rounded and the premaxillary teeth are relative- 
ly much larger. The sculpture is more delicate with the ridges more acute. The orbits 
and nares are not defined. The maxillary is well preserved for a length of an inch ; its 
teeth are smaller than the premaxilliries ; I count four in a line ; crown simple conic. 
External surface of maxillary not very strongly sculptured. 

This species cannot be referred to its genus without further material. I therefore do 
not name it. 


Quart. Joum. Geol. Soc. X., 1853, 81. Dawson, Loc. Cit. 
Coal Measures. Joggins, of Nova Scotia." 


Canadian Naturalist and Geologist, VIII., 161. 
Coal Measures : as the last. 



Joum. Geol. Loc. Lond. Loc. Cit. Dawson, Canadian Naturalist and Geologist, VIII., 272. 
Carboniferous Coal Measures. The Joggins, Nova Scotia. 


Proceed. Ac. Nat. Sci., Phila., 1868, 214. 

This genus is indicated by two rami of a mandible and a portion of a premaxillary 
only. These, when compared with those of GEstocephalus, and Dendrerpeton, from the 
same locality, and with others described by authors, are so much stouter, i. e., shorter 
and more elevated, that they evidently belonged to a genus not hitherto known. The 
genus further differs from Oestocephalus, in having the teeth of equal size to the poste- 
rior parts of the series, that is, to the base of the elevated coronoid process. The teeth 
are elongate cylindric cones, with their acute tips turned a little posteriorly. The frac- 
tured ones display a large pulp cavity. The three premaxillaries preserved are similar, 
but without curvature of the tips. They do not exhibit strise or any other sculpture. 

So far as the remains known go, the genus is nearer Hylerpeton than any other. 
According to Dawson that genus is provided with a large canine-like tooth, at the ante- 
rior extremity of the maxillary, on the inner row, which is inserted into a distinct socket. 
No such tooth appears among those of this genus. The latter does not give any indica- 
tion of the very elevated coronoid process of Brachydectes, though the external portion 
of the dentary bone in that region being lost, little can be said about it. Prof. Owen's 
plate indicates a ramus whose depth at the last tooth enters 8| times the total length. 
In our species this depth enters about 5 times. 


This species is represented by one nearly perfect ramus mandibuli, one dentary bone, and one premaxillary, prob- 
ably not complete. 

The dentary bone appears to have been attached by suture to the articular and angular, as its free margin has 
very much the outline of that suture in Amphiuma and lizards. The coronoid process would also seem to be a part 
of the same bone as in Amphiuma and Menopoma, and not composed of a coronoid bone as in lizards. It rises im- 
mediately behind the last tooth, and displays no suture. 

The lower portion of the dentary is prolonged into an acute angle. This is separated by a deep and wide con- 
cavity from the superior posterior prolongation, which is obtuse and rises at once into the coronoid process. Teeth 
on this dentary seven ; the same number is on the preserved ramus ; this number is suspected to be complete or 
naerly so. The teeth terminate at the obvious termination of each ramus, which is, it is true, slightly obscured. 
These teeth are the longest of the Microsauria in relation to the depth of the ramus, equalling the largest in (Estc- 
cephalus. They are doubtless exposed, as are some of those of the last named genus, by the splitting away of the 
outer parapet of the dentary bone. As no traces of alveoli have been thus rendered visible, I suspect the dentition 
to have been aerodont, as in some existing Batrachia. 

No external surface of the mandible remains, but there are no impressions of sculpture on the matrix. A little 
external face of the premaxillary displays none. 


Measurements. Lines. 

Preserved length of ramus (imperfect), 11 

Depth at last tooth, 2 

Length of exposed tooth, 1.7 

Length dentary, 7.5 

Depth at coronoid, 3.5 

Do. at first tooth, 1.3 
In the mandibular ramus of the Hylerpetou dawsoni,' there are according to Owen at least nine teetli ; in the 
present species there are but seven. 

Proceed. Acad. Nat. Sci. Phil. 1868, p. 215. 

This genus embraces a single species only, as I at present understand it. The 
extremities are well developed, and the body is stout and lizard-like. It is represented by 
but one individual which has been spread over a surface of the coal slate, exhibiting ventral 
armature, dorsal region with ribs, and anterior and posterior limbs. Of skull and caudal 
vertebra; nothing remains. 

The dermal riblets are arranged as in Urocordylus, i. e. in parallel lines directed 
obliquely forwards and continuous on the median line, forming there a chevron directed 
forwards. The stria? are not so closely placed as in O. pectinata, but are separated by 
grooves wider than themselves. 

The humerus, idna and radius, are rather stout, and of a size relative to the body, as 
in common types of existing sauria; the ulna and radius separate. There is no carpus, 
but five well developed digits have phalanges in the following numbers, commencing on 
the inside, 3, 4, 5, 6, 5. The last phalange of the second is obscured, and it is not 
positive that the number is as given ; it is more probable than that it should have been 3. 
The outer toe has been more slender than the others; the distal phalanges of all the toes 
are short conic, as in Salamanders. Thus this form differs much from Ampliibamus, 
where the numbers are 3, 3, 4, 5, 4, showing a lower development of limbs. 

The ribs are long and curved as in Reptiles, and judging by their distances the 
vertebra? are short; the latter are not well defined but there is no indication of prominent 
spines of any kind. 

The pelvic bones and portions of those of the hind limbs are present, but so obscured 
and confused as not to be made out. Enough remains to show that the hind limbs are 
considerably longer than the anterior. 


Proc. Acad. Nat. Sci. Philadelphia, 1808. 210. 

This species had a length of body about equal to that of a fully grown Chamseleo vulgaris of the largest size or 
of a half-grown Menopoma. Thirteen ribs on one, and several on the other side, are preserved; where they 
terminate, probably at the pelvic region, some small or rudimental ribs project from the two or three first caudals. 
Three ribs and their interspaces extend over five lines. The humerus is broken, but its length can be clearly made 
out to be seven lines ; it lias no condyle, and is dilated at both extremities. The ulna and radius are distinct, 
truncate, hollow, and dilated at the ends. Length of ulna 5.1 lines, distal width 1.8 lines. Carpus not ossified. 
The fourth toe is considerably longer than the others, the fifth is next and reaches the basal third of the antepenult 
phalange of the fourth ; the third is very little shorter ; the first is not quite so long as the first two of the third. 
The bones of the hind limb are not readily distinguished. They are evidently much longer and larger than the 
anterior ; no part of a foot is preserved. 

This form is probably allied to Urocordylus. It has relatively much stronger ribs in relation to the vertebrae 
than we have seen in that genus, and there is no evidence of the existence of the vertebrae characterizing the latter. 
The limbs are relatively much stronger than in CEstocephalus, and it lacks the peculiar dermal armature of 
that genus. 

Proceed. Acad. Nat. Sci. Phila., 1808. 218. 

This genus is represented by a more complete series of remains than any other of the 
Linton bed. 

As before remarked, it represents in many respects, the Ophiderpeton of Huxley, and 
has been alluded to by Dr. Newberry as allied to it. It however, differs markedly in 
the narrow lanceolate form of the head, with probable accompanying peculiarities of 
detail, and in the presence of limbs, which have not been found in the Irish genus. The 
form of the head is somewhat nearer that of Lepterpeton Huxl., but the remarkable 
form of the spines of the caudal vertebra? so characteristic of the American genus, are 
not found in Lepterpeton. In this latter respect it is allied to the LTrocordylus of 
Huxley, recently discovered in the Coal Measures in Leinster, Ireland. It differs only in 
the presence of elongate lizard-like ribs and in the absence of " oat shaped scales" of the 
lower surfaces. 

It is a matter of much interest in American Palaeontology that this remarkable type 
should be found to occur in our Coal Measures. It was first announced by Dr. Newberry 
at the meeting of the American Association for the Advancement of Science for 1867. 
(See p. 144), as an ally of Urocordylus and Ophiderpeton. 

The forms discovered by Dr. Newberry have an interesting relation to those of 
Ireland, such as types of the present period frequently present. 

The characters of Oestocephalus are: neural and ha?mal elements of the caudal 
vertebra?, elongate, distally, dilated and grooved, attached by contracted bases. Ventral 
aspect defended by a close series of oblique dermal rods on each side, which meet anterior- 


ly on the median line. Limbs distinctly developed. Ribs long, well developed. Scales 

In more detail, we have an elongate lanceolate head with little or no sculpture of the 
external surface of the bones. The angles of the mandibles are much prolonged 
backwards as in Apateon and frogs, and the well developed ribs commence but a short 
distance behind the head. The vertebrae are slender, and furnished with well developed 

The neural spines of dorsal vertebrae in O. remex are flattened and expanded in the 
line of the vertebral column, and weakly grooved to their superior margin. Their char- 
acter has not been observed in the other species. 

The neural and haemal spines of the caudal vertebrae are prolonged, and remarkably 
sculptured by longitudinal grooves, which are most distinct towards their terminations. 
They are much flattened to support an oar-like tail. 

Anterior limbs have been seen in two species, and posterior in one other. Though 
they all probably possess two pairs of limbs, this point is not entirely established, leaving 
the "homogeneity of this genus still somewhat uncertain. 

A pair of symmetrical bones whose impressions are seen posterior to the occipital bone 
appear to be the coracoid, and one of them is followed by a second element, which is 
probably the humerus. A third piece follows, which is ulna, or radius; the second bone 
of the forearm is lost, but some impressions, which appear to be those of a digit, are 

The skin has been occupied by a great number of closely packed, curved, spine- 
shaped scales. They have occupied the ventral integument, passing from the median line 
of the belly outwards and posteriorly, having acute tips which may or not have penetrated 
the skin on each side. No such tegumentary spines protected the dorsal region. 

The three sculptured dermothoracic plates common to so many of this order, have not 
been seen in this genus. 

As compared with Sauropleura, this genus is more elongate and snake-like, and with 
much weaker limbs; these characters are not sufficient to distinguish it alone, but as no 
dilated neural spines nor similar abdominal armature are discoverable in the former, I 
prefer to keep them separate for the present. 


Sauropleura remex, Cope. Proc. Ac. Nat. Sci., Plrilada., 18G8, p. 217. Oestocephalvs amphiumintts, Cope. 
1. c. p. 218. 

Additional specimens received from Dr. Newberry enable me to combine the caudal 
vertebra? described as above under the genus Sauropleura, with the remainder of the skel- 



eton which was the type of the present genus. The species thus constituted is 
represented by five specimens and their reverses, and a fifth may be added with much 

They indicate an animal of the average size of the Amphiuma means. 

The extremities of the vertebras are denply concave, but the centra are so long as to prevent the concavities en- 
tering more than one-fifth of the latter, each. The diapophyses are behind the middle, and are broad, curved back- 
wards, and acuminate as in Amphiuma. The centra have a prominent median line below, with a longitudinal con- 
cavity on each side. Five of them a little exceed an inch in length. Neural spines moderate. The hu- 
merus is longer than the coracoid, and is considerably dilated distally ; the coracoid slightly dilated at its superior 
extremity. The dermal armature commences immediately behind the head, and forms a band of 14 lines in width ; 
measuring across the spine-like scales, in a width of a line, four cylinders may be counted. The external portions 
are curved backwards, the interior nearly straight, those of the anterior series more delicate than the posterior. 

The head is wedge-shaped, with regularly acuminate sides. The top of the cranium is somewhat broken in the 
specimen ; the portions preserved are smooth, and the longitudinal suture is distinct for a considerable distance. 
The angle of the mandible is produced considerably behind the occiput, and is enlarged and rounded. The end of 
the muzzle is broken away, and the region of the orbits so fractured as to render their precise location uncertain. 
The superficial layer of the cranial bones is nowhere clearly visible, so that it cannot be ascertained whether it is 
sculptured or not. The quadrate bone projects well posteriorly. Some fragments indicate small cylindric teeth, as 
in Amphibamus, but they are not characteristic. 

Measurements. Lines. 

Length cranium without muzzle. 17.3 

Width do posteriorly, 11.5 

Length of the coracoid, 2.1 

Length humerus, 2.5 

Length of sixth vertebra from skull, 3 

Extent diapophyses, 3.S 

Width centrum, 1.5 

The characters of the genus are further shown by a part of another individual in the same coal slate matrix. 
The cranium and anterior portion of the vertebral column only are preserved, the latter so much injured as to render 
the vertebral characters very obscure. As in the other, the bristle-like scales extend along the dorsal retriou to 
near the cranium. The anterior | of the ventral side shows a large number of oval scale-like bodies, which 
belonged undoubtedly to the animal, and were probably dermal scales. They are, however, neither regular in 
from nor position. Close behind the head two or three long bones of the fore limbs have been exposed. They are 
slender and similar to those of the last specimen. 

The cranium, though without the muzzle, shows its long wedge shape. The maxillary bone cannot be distin- 
guished, nor can the orbits be made out. One ramus mandibuli is pretty well preserved ; it shows no coronoid pro- 
cess. Thirty-one teeth may be counted on a portion a little more than one-third its length. The anterior eleven of 
these are abruptly longer and stouter than the others. They are all, except a few most anterior, in pairs, i. e., with 
a slight vacancy between every two. The larger ones where broken at the bases exhibit a moderate pulp cavity ; 
the smaller, a large one extending to near the lip. Several, though not all of the larger teeth, display a shallow 
groove on the external face to near the tip, which is probably owing to pressure and a partial crushing. The 
points of the larger teeth are more abruptly acute, and turned abruptly _backwards. A portion of their increased 
length (.35) is to be attributed to the splitting off of the external dentary margin, and the exposure of the roots. 
No alveoli are shown, and the dentition is probably by anchylosis of expanded base as in true Labyrinthodonts . 

A third series, Nos. 26, 29, Mus. Newberry, of dorsal vertebras is without head or limbs. The vertebrae are 
elongate, three of them extending over 2.10 mm. The neural spines are longer than high, and are nearly in 
contact at their margins ; each is marked by about five obtuse vertical ribs. A fractured section of the abdom- 
inal dermal spines in place, displays at least six superimposed layers of them. 



This species is larger than the O. pec- Fig. 2. 

tinatus, and about equal to the Urocor- 
dylus wandesfordii Huxl. The caudal 
spines differ in the greater attenuation of 
the neural series, and the presence of a 
basal lamina on the haemal. The caudal 
region is represented by a portion of the 
vertebral column three inches in length. 
In this space may be counted twenty-four 
vertebra. Such of the latter whose out- 
lines are visible, display centra character- 
istic of the genus ; their terminal concavi- 
ties conic, with apices meeting in the 
centrum, medially ; zygapophyses rudi- 
mental if present. 

Characteristic of the species are the 
remarkable length and slenderness of the 
fan-shaped neural and haemal spines, and caudal vertebrae, nat. size. 

the absence of an acute serration on their margins. In this species the spines have a laminiform expansion at the 
base in their plane. In the other species here described these spines are not only relatively broader and more fan- 
shaped, but they are acutely serrate on the margin and constricted at the base. 

In C. remex the dilate haemal spines are a little more than three times as broad distally, as they are long, 
while the neural spines are a little narrower. The haemal spines stand about the middle of the centrum. The 
basal half is furnished with an anterior ala, which leaves the anterior margin rather abruptly and extends to the 
next spine in advance. It returns gradually to the centrum and is separated from the articular face of the latter 
by a notch. A similar ala exists on the posterior margin of the haemal spine, which extends for a shorter distance 
above the base, and is narrower than the anterior. Each spine presents a median groove on its surface, which 
extends half way to the base or further ; on each side of this are some three other grooves which extend but a 
short distance ; surface otherwise smooth. The ends of the grooves slightly notch the truncated end of the spine. 

The neural spines are on the posterior portions of the centra, and not in contact with the bases of those adjacent. 
They are without the dilatations of the haemal spines, and are directed rather more obliquely backwards. They 
are similarly grooved, though without that so distinctly median, seen in the haemal series. 

Both neural and haemal spines become stronger towards the anterior part of the vertebral column. There 
appear to be no zygapophyses nor diapophyses, nor rudiments of ribs. The centra are rather stout and somewhat 
constricted medially. There are no traces of dermal armature of any kind. 

Length of a posterior centrum, 
Depth do. do. do. 
Length haemal spine of adjoining vert., 
Basal width, 
Median width, 
Distal width, 

Length of a more anterior haemal spine, 
Distal width do. do. do., 
Length anterior neural spine, 
Width do. do. 




From the Coal Measures, the Bituminous basin at Linton, Columbiana County, Ohio, near the Ohio River. 
Prof. J. S. Newberry. 



Sauropleura pectinata, Cope, loc. cit., 1868, 218. 

This species is represented by portions of the vertebral columns of four individuals. In two of these, vertebral 
centra are discoverable, in one quite definitely. They are slightly constricted medially, and without ridge or 

The neural and haemal spines of superior and inferior lines are similar, and in the specimens undistinguishable. 
The dilated portions form nearly equilateral triangles, which stand on moderately short pedicels. They are weakly 
ridged, and each ridge is prolonged into a narrow acute tooth, beyond the margin of which eleven may be counted 
on one of the best preserved. The longitudinal striae are terminated near the pedicel by two others which cross 
obliquely from each side and meeting present an appearance similar to an overlapping of each margin. The 
edges of the spines form a continuous line. 

As in the other species, there are no indications of other processes, nor of dermal scales. 

The smallest of the specimens shows that in front of the region furnished with the peculiar spines described, the 
body is furnished with a mass of bristle or hair-like scales. The grooved neural spines are slightly displaced 
anteriorly, and the bristle-like mass looks like a continuation of their striae, and it is not easy to find any line of 
demarkation between them. The serrate spines are further forwards on one side than the other. These 
liuear scales were arranged as in other genera, in lines which converge forwards to the median line. They are 
somewhat obscured in the specimen, but it cannot be determined that they are continuous on the median line. 
Whether this is the posterior or anterior portion of the body cannot positively be determined from the specimen ; it 
is, however, most likely the posterior, for near the posterior portion of the striate surface a weak pair of 
limbs is given off on each side. On the right, a moderately stout femur is followed by a broken tibia 
and fibula, and by five slender, closely oppressed metatarsals. The last are about 2-5 as long as the space 
between them and the femur : beyond them a few slender phalanges are moderately distinctly defined. The 
tibia is more distinct on the left, but no tarsus or phalanges ; some of the metatarsals are preserved here 
also. Length of limb to end of metatarsals equal to five vertebras in juxtaposition, measured along the edges 
of the neural spines. The limb has been slender, especially the hand. 

The above specimen enables me to assign as the ventral armature of this species a closely packed series of 
V-shaped grooves which lie in connection with an obscure vertebral column, on the block containing one of the typical 
specimens of this species. They are not continuous with any of the series exhibited on other parts of the block : 
some of these at least are the doublings of the slender animal, and this ventral portion has been displaced. The 
grooves are like the impressions of haemapophysial rods, vastly more numerous however than the number of 
vertebrae ; they are really the dermal armature. Huxley figures a portion of this as on the block with the 
Urocordylus wandesfordii, but does not refer it to a precise relation to the animal. A few well developed ribs are 
preserved with this portion, the only ones I can refer to this species. The vertebrfe are partly enclosed in matrix, 
partly impressions. The neural spines, though expanded anteroposteriorly, are less elevated than in the caudal region, 
and have left no traces of their characteristic ribs or serration. 

The number of spines in the type specimens is six in a half inch ; in the smallest, just described, ten in the same 
distance. The height of the spine in the former 1.15 lines. 


Loc. Cit. 1868, 220. 

This genus is established on remains represented by three specimens, which are two 
series of dorsal vertebrae. with ribs, and a series of caudals. One of the dorsal series 
embraces sixteen vertebra?, the other fourteen, the caudal series, twenty-two. 

From its serpentine form this genus may be compared with the Dolichosoma of 
Huxley, though a close relation does not exist between them. In the Irish genus, the 


series of caudal vertebra; is quite short, and the ribs are short and but little curved. In 
Molgophis the tail has been like that of an elongate serpent, and the ribs are a> well 
developed as those of many reptiles. 

Though no limbs or arches can be certainly found, a rather quadrate, parallelogrammic 
piece, about as long as the diameter of a vertebra, may be found. This is however verj 

The characters of the genus are: a long serpentine body, without dermal armature, so 
far as discoverable; the vertebra? large and broad with very prominent zygapophyses and 
moderate neural spine, those of the caudals without narrowed bases (and grooved or 
serrate edges, most probably). Limbs and cranium unknown. 

This genus differs from Urocordylus in its caudal vertebra?, and from Ophiderpeton in 
its dorsals: the latter in their zygapophyses projecting laterally resemble those of Amphi- 
uma. It differs from OEstocephalus in the absence of ventral dermal bands and in the 
longer body, without indication of limbs. The size of the vertebra? would indicate a body 
of the size of a rattlesnake, (C. horrida,) and therefore too large for the species named 
Brachydectes neicberryi. 

The ribs are long, and though the head is not bifurcate, there appear to be both 
tubercle and head on the dilated extremity. They show themselves where crushed to 
have a large median vacuity. 


The neural arches viewed from above have a posterior V-shaped outline, from the fact that the broad zygapo- 
physes meet on the median line, and spread out distally over the broad anterior ones adjoining. The latter appear to 
be somewhat concave, and to border the former exteriorly as well as inferiorly. The base of the neural spine extends 
to the posterior emargiuation, but not quite to the anterior. The breadth of the dorsal vertebra above is equal from 
the emargination behind to the anterior margin of the anterior zygapophysis. 

The caudal series must have been very long, as there is very little diminution in the size of the vertebrae through- 
out the series preserved. They present much the same form as the dorsals, but are more contracted medially, and 
the zygapophyses have a more transverse direction. There may indeed be a diapophysial element beneath these, but 
the two cannot be distinguished if so. They are connected by longitudial impressions, indicating the existence of 
the tendinous bands in the longitudinal muscles seen in Amphiunua, or the osseous spicules in the same situation in 
birds. The neural spines indicated by their narrow bases, occupied the length of the neural arch, and remind one of 

The ribs are long for a Batraehian, but shorter than in a reptile. They are well curved, chiefly near the proximal 
extremity. The longest I can find measured by a chord, equals two vertebrae and two-fifths. Three vertebra? 
measured along the median line above equal eleven lines ; one of these is 3.6 lines in width above : width of a :' 
posterior caudal 3 1. 

This animal has been like Amphiuma a snake-like Batraehian, but probably of even more elongate form. How 
near its affinities to this genus may be, cannot be ascertained, owing to want of important parts of the skeleton, but 
it differs in the important feature of the large, well developed ribs. 





This genus is proposed for Ganocephala, allied to Apateon ( Ardiegosaurus ) but differ- 
ing as follows : 

There are no traces of vertebral centra or spines, or of ribs, in portions of six individ- 
uals preserved. No sclerotic bones can be found in one cranium partially preserved. 
There appears to be two pairs of very short limbs. The usual three sculptured pectoral 
bones are present, consisting of a rhombic medial, and a pair of half rhomboid laterals. 
The abdominal region is protected by series of scales which extend obliquely forwards to 
the medial line, where they meet, forming chevrons. They are closely approximated, 
and are composed of rhomboidal scales which have a convex external and internal face, 
in transverse section, and which overlap at the extremities, and are in contact by faces 
which are oblique in both the longitudinal and transverse directions. 

The exact form of the muzzle cannot be made out. It is, however, not elongate, nor 
yet of the broad rounded form of Pelion. Several teeth are preserved. There are 
two kinds, which occupy the margins of the maxillary and dentary bones. The 
anterior teeth appear to be longer than the posterior, though the latter are mostly 
broken off. Most of the teeth are coarsely incised sulcate for perhaps their basal half. 
Two long teeth behind their distal extremity of the dentale, are on the other hand very 
finely and sharply striate for their basal half; the tip is subcylindric, and very prolonged 
and acute. A small, dagger-shaped tooth near the base of one of the posterior, may be- 
long to the successional, or to a small outer series. A series, of four elevated tooth bases, 
with a broken crown, of much smaller size than those of the jaws belongs to the vomerine 
or a palatine series. The row is single and uniform. 

The superior face of the cranium is injured, but the component bones appear to have 
possessed a radiating sculpture of no great distinctness. 

The form of the body seems to have been long and fish-like, with little contraction near 
the limbs. Caudal extremity is not preserved. There were probably two pairs of very 
weak limbs, of which three metacarpals of the anterior are preserved. A narrow longi- 
tudinal bone extends posteriorly from the lateral pectoral bone. Its extremity is broken, 
but a flat, narrow, longitudinal bone, with a dilated extremity curved outwards, may be- 
long to it, or be the humerus. I find no distinct traces of branchial arches. 

The affinities are thus obviously to Apateon, and it is not beyond possibility that future 
investigations may prove it is the same, though this is not probable at present. 

Portions of seven individuals of one species, and of one individual of another, were 
discovered by Prof. John S. Newberrv at Linton, Ohio. They differ as follows : 


Pectoral bones with strong elevated radii and very weak reticulation in the centre of 
the median. The abdominal scales thick, many in a transverse series. 


Pectoral bones nearly as above; the abdominal scales slender, not more than three in 
a lateral transverse series. 


Pectoral bones — the lateral finely pitted, the pits becoming elongate towards the 



One of the specimens of this species consists of a supero-lateral view of a crushed cranium and anterior part of 
the body. The median pectoral bone appears as a sagittiform plate with thin edges, rounded lateral angles and a 
thin median prolongation behind. The greater part of the borders of the right orbit are distinct, and display the 
continuity of the malar and supratemporal regions. The ramus mandibuli is longer than the cranium proper. The 
number of the teeth cannot be determined, but they are rather large, and traces of their existence do not extend 
behind the orbits. The length of the long anterior mandibular tooth is .5mm., and the diameter at the base .1mm. 
Diameter of base of a superior maxillary .'2mm. The approximate length of the mandibular ramus is .0715m. long ; 
longitudinal diameter of the orbit 73mm. ; length of median pectoral plate .03Gm. ; width of same .019m. 

Other specimens (Nos. 4 and 10 coll. J. S. Newberry) show that the abdominal scutellation commences 
immediately behind the pectoral bones. Those near the median line are similar to the external, and they unite in a 
zigzag line. The depth of these scales is oblique, and is somewhat greater than the width. Thus one angle 
projects, and gives the surface a somewhat ribbed rather than continuous character. The following measurements 
express their dimensions relative to other portions of the body. 


Width of median pectoral. .0138 

Do. three pectorals restored, .054 

Do. scale band, .064 

Scales in .01m. transversely to series, 5.2 

Do. longitudinally do., 1.75 

Radii of lateral pectoral crossed by .01m., 7 . 

Length ulna and radius, .0108 

Do. metacarpus, .000 

The above measurements express the small size and weakness of the fore limb. Another specimen (No. 18) in 
which the impressions of the scales are of the same size as those of the preceding, the impression of what may be 
femur and ulna and radius are visible, which are of considerably smaller size than the one above mentioned. They 
are but doubtfully these elements. 


Length proximal element, 004 

Do. two distal do., .0038 

A median pectoral plate of a seventh and much larger individual than the preceding is prolonged anteriorly 
and posteriorly. The broad posterior portion is transversely ribbed, the ribs weaker and interrupted medially. 
Length .063m.; with .04m. 

This very interesting form is part of the unique and important collection made by Prof. J. S. Newberry, at 
Linton, Columbiana County, Ohio. 



A very elegant sculptured median pectoral plate represents this Batrachian. It is larger than most of 
those of C. radiatus, but smaller than the one last described. The posterior and median parts of the plate 
are pitted to the number of six in five mm. The pits are separated by sharply defined ridges. They elongate 
towards the anterior parts of the plate, resembling elongate hexagons, and the ridges approaching radii, though 
not more elevated than the cross septa. The bevelled margins are rugose also, except at the edges. 

Length of the bone. .045 

Greatest width, .025 

Width posterior margin, .021 

From Linton, Columbiana Comity, Ohio. Prof. .1. S. Newberry, Coll. No. 20. 

Sp. nov. 

This species is represented by a specimen of very much smaller size than either of the preceding. That it is not 
the young of C. crassiscutafrus is indicated by the peculiar form of the dermal ventral scales, and by the greater 
anterior prolongation of the median ventral dermal bone. 

The specimen is lying on its back, displaying the ventral armature somewhat disturbed, and broken through in 
some places, where the vertebra? and ribs would be discerned if they existed. The head is turned abruptly to one 
side, and is apparently right side up. Several of its elements are scattered on adjacent portions of the block. 

The head is of an elongate lanceolate form. The upper surface of the frontal bones is punctate-rugose in relief, 
with short radii towards the margin. The distal two-thirds of the mandible is narrow wedge-shaped ; the external 
surface is coarsely pitted. There are no teeth preserved. The sutures of the cranial bones are of the squamosal type 
or fish-like. 

The three thoracic shields are considerably displaced. The lateral are subtriangular, and are strongly ridged 
towards the inner margin. The median shield is short spatulate, the narrow portion directed anteriorly ; the posterior 
rounded. It is coarsely pitted medially, and coarsely and strongly radiate ridged to the margin. Immediately behind 
these plates the dermal armature commences. It consists of elongate, narrow, subcyhndric scales, which are arranged 
end to end, in series which meet on the median line, converging anteriorly, as in the other types here described. At 
first sight they resemble the long rod-like pieces of (Estocephalus, and careful examination is needed to detect the 
interruptions caused by the sutures of the scales. The latter are several times as long as wide, and appear to be 
terminated by oblique faces as in the typical species. 

The trace of limbs is only seen in a short impression resembling that of a humerus behind the thoracic buckler. 
Nothing can be found pertaining to posterior limbs, but some laminae and impressions in the position of pelvis, but 
not immediately connected with the other portions of the skeleton, may belong to the latter arch. 

Measurements. MM. 

Length of body to buckler, 4.2 

"Width of ventral armature, .8 

Impression of humerus, (or coracoid,) .2 

Length median thoracic plate, 1-15 

Width " " " .51 

Length fragment under jaw, .75 

Depth do. at middle. .15 

Width end muzzle, .29 

This species, like the preceding, is from Dr. Newberry's collection, (No. 13,) and from the Linton coal bed, South- 
eastern Ohio. I have dedicated it to Prof. Othniel C. Marsh. Professor of Palaeontology in Yale College, Connecticut. 





Proo. Ac. Nat. Sci., 1856, 256, Emmons' Geology Nor. Amer. p 59. Tab. 
Triassic Coal Beds, Chatham County, North Carolina. 



Quart. Journ. Geol. Soe. Loud., X., 1853, Tab. (XI notes.) 
Carboniferous Coal Measures of the Jog-gins, Nova Scotia. 



Mastodonsaurus durus, Cope. Proc. Acad. Nat. Sci. Philadelphia, 1866. 249. 

A portion of the table of the cranium of a large labyrinthodont accompanied other fragments of the same in a bed 
of hard black shale, according to Wheatley's section of the Trias at Phcenixville, Pa., (in Silliman's Journal Sci. 
Arts, 1861, 45.) about 181 feet from the top of the series, while a tooth formerly described with it is from near 83 
feet higher, in "the Plant bed." The Belodon comes from the same as the last. 

The largest fragment is eight inches long and eight and one-half wide, and is a portion of the table of the 
cranium exhibiting the usual medial depression and embracing portions of the postorbital and parietal bones ; one 
of the former is four inches six lines long ; both are pitted medially (about 3j pits in an inch) and marked 
with short coarse sulci posteriorly. The parietals are two inches nine lines wide behind, and four inches wide 
between the anterior parts of the postorbitals. On what is probably the posterior part of the interorbital region 
(a small part of the posterior margin of the left orbit is preserved) commence two smooth, shallow sulci 1 in. 2 1. apart, 
which are probably the posterior extremities of the superficial channels of the face of the Labyrinthodonts. Between 
them the surface is pitted (four or five to the inch). The parietal bones are throughout longitudinally sulcate (four 
and one-half to the inch), with obtuse ridges between. The parietal fontanelle was not discoverable, nor could the 
form of the orbits be certainly determined, though they were probably not large. 

From the Triassic Red Sandstone near Phcenixville, Chester County, Penna. Discovered by Charles 51. 

Teeth subcylindric, with large pulp cavity at the basis only : external surface without grooves ; dentine divided 
by numerous flat vertical laminae of a dense substance, probably enamel, which radiate from very near the pulp 
cavity to the external enamel layer. 

I have been much puzzled with the teeth which I described (I. c.) in the above language, as typical of this genus. 
Their constitution has been chemically altered, and the section exhibits the radii of a denser material which unites 
at right angles with a sheath of the same substance which envelopes the tooth externally. 

The teeth are of various sizes, sometimes two inches long and more slender in proportion to the length than those 
of the Mastodonsaurus jaegeri and salamandroides ; they are cylindrical, gently curved and acuminate without 
external sulci : of the minute sculpture little can be said, but the casts of the surface are smooth. The roots exhibit 
a short conic pulp cavity. In a few weathered sections the denser radii are well displayed. 

They are not convolute as in Labyrinthodonts, but perfectly straight and convergent to a minute central vacuity. 
In a tooth four lines in diameter there appear to be five principal radii, which though exceedingly delicate may some- 
times be seen in longitudinally fractured specimens. 

*The Centemodon sulcatas Lea which I referred here in my synopsis of Extinct Batrachia, Proceed. Acad. Nat. Sci., 186$, may be placed among the 
Thecodonts. I was induced to place it here by Lea's ascription of sulci and pulp cavity to the tooth, which I did not understand properly. 



These 1 suspected to indicate the positions of inflections of enamel, as it is difficult to imagine sucli regularly 
radiating fractures. I cannot however, be entirely sure that this is the case. Under a low power neither the 
radii nor interspaces exhibit any structure ; the small pulp cavity is filled with the sandstone matrix in which the 
tooth is enclosed. It may be supposed that the relatively denser structure of the enamel has been preserved in the 
slow alteration which the composition of the tooth has undergone. They thus project on weathered or ground surfaces. 

The species to which these teeth pertain was originally described by the writer as a Mastodonsaurus. The 
latter genus however exhibits external grooves where the inflections of enamel enter and separate the dentine. These 
inflections, as is well known from the figures and descriptions of Professor Owen, are more or less convoluted, some 
of them very highly so. The lamina? of the teeth of the Eupelor cannot be looked upon as inflections of enamel, but 
rather as branches. They are exceedingly thin, and our sections do not demonstrate them to be double. If they are 
double, they are very much more attenuated than the external enamel stratum. They may be distinguished in a 
section of the wall of the pulp cavity at the base of the root as well as elsewhere. 

The fluted tooth referred to in my original description, in which this structure is observable, belongs apparently 
to a Thecodont, perhaps to Belodon : other teeth of this genus which I have seen present the same peculiarity. As the 
tooth from which the description of Eupelor was derived, is from the same stratum as the Belodon and Clepsysaurus, 
and some distance above the horizon of the cranial bones described, after an examination of the series in possession 
of Wheatley, I am disposed to refer all these teeth to the Thecodonts, and restrict the name Eupelor durus m. to the 
cranial bones only. 


The following preliminary table exhibits the more essential characters of the orders 
of Reptilia, as understood by the writer :* 

I. Supratemporal and postorbital bones present; extremital portions of limbs not 
differentiated ; quadrate bone united by sutures. 


II. No supratemporal or postorbital bones ; extremital portions of limbs differentiated. 
A The quadrate bone united by suture to the prootic, the opisthotic and the quadra- 

tojugal bones. 

« The scapular arch continuous, including the sternum, which is anterior and simple. 


aa Scapular arch not continuous, sternum inferior, extending posteriorly, composed of 
at least eio-ht elements : dorsal vertebra? sacrum-like. 



A A The quadrate bone not united with the prootic, and articulating freely with the 
opisthotic ; no quadratojugal. (Streptostylica.) 

Sacrum from three to five vertebras ; anterior extremities excessively elongated for 
flight ; acetabulum complete ; pubes longitudinal, distinct ; exoccipital not distinct. 

* Many of these groups correspond with those proposed by Prof. Owen. 


Opisthotic united with exoccipital ; brain case not closed before prootics ; palatines 
united all round ; sacrum of two or one vertebra ; pubes transverse. 


Opisthotic distinct and distally free from the cranium ; brain case partly closed before 
prootic, palatines united. 


Opisthotic distinct, free from cranium except proximally ; brain case nearly closed 
anteriorly, palatines attached behind only. 


Elements of the limbs beyond the humerus not differentiated, in indefinite number. 

Postorbital and supertympanic bones over the temporal fossa. 

Quadratum solidly united by suture with the prootic opisthotic and quadra tojugal. 

Sacrum none. 

Pubes and ischia transverse and in contact. Neural arches free. 

Premaxillary divided. 


Elements of the lirnbs, of the pes and manus differentiated, in definite number. 

" Postorbitals and supra temporals " of Owen wanting. 

Quadratum immoveably united by suture with opisthotic, prootic and quadratojugal. 

Sacrum of from one to six vertebrae. 

Neural arches attached by suture in most. 

Premaxillary divided. 

Cranial walls cartilaginous anteriorly. 

Palatine bones in contact with maxilliaries, and united by suture with them. 

Circulatory System (known only in the Crocodilia). Heart with complete septum of the 

ventricles ; a communication between aorta roots. 
Nervous System (known only in the Crocodilia). Cerebellum with small lateral lobes and 

weak plicae. 


Parts of limbs differentiated. 

Dorsal vertebrae without mobility : no clavicle, a procoracoid continuous with scapula : 

ilium vertical, acetabulum complete. 
Sternum not in connection with coracoid, composed at least of eight or more bilateral 

elements, and extending posteriorly to beneath the pelvis. 


Teeth none. 

Quadratum immoveably fixed by articulation with the large pro and opisthotics. 

Cranial canity not ossified anteriorly; no ali or orbitosphenoid. 

Palatine bones attached anteriorly. 

No postorbital or supratemporal elements. 

Two sacral vertebra; : ischia and pubes more or less transverse, the latter sometimes not 

in contact. 
Costal and vertebral elements usually united into a dorsal shield : dorsal corium ossified. 
Circulatory and Nervous Systems, much as in Lacertilia. 


Limbs differentiated, one digit excessively elongated for aerial progression. 

Postorbital and supratempoial roof wanting. 

Sacrum of from three to five vertebra?. 

Inferior pelvic elements distinct, the pubes set parallel, directed forwards and not joined. 

Neural arches consolidated. 

Palatine elements united ; one premaxillary. 


The distal parts of limbs differentiated ; no supratemporal or postorbital bones. 
Quadratum not in contact with prootic, articulating freely with opisthotic ; no quadrato- 

Opisthotic sessile not distinct. 
Sternum composed of but two elements, which are continuous with remainder of scapidar 

Cranial caAdty not ossified anteriorly to prootic. 
Palatine bones solidly attached to maxillae; a symphysis mandibuli. 
Squamosal usually present; premaxillary usually single. 
Limbs ambulatory, when present. 

Sacrum of two vertebra;, when present ; ribs single headed. 
Neural arches not united by suture, chevron bones present. 
Pubes and ischia transverse, united in pairs. 
Circulatory System. Heart with imperfect septum atriorum, no communication between 

aorta roots. 
Nervous System. Cerebellum without lateral lobes or plicae. 



Characters of skeleton as the preceding, except : opisthotic distinct, prolonged from the 

cranial walls as suspensorium of the quadrature. 
Xo symphysis mandibuli. 
Squamosal present ; premaxilliary single. 

Cranium with alisphenoid and parietal developed in front of prootic. 
Limbs inflexible, natatory ; sacrum none ; chevron bones. 
Neural arches not attached to centrum by suture. 
Pubes and ischia wanting. (!) 


Characters of Lacertilia except : opisthotic free, distinct from the cranium except proxi- 
mally, supporting quadratum ; no squamosal. 

Cranial cavity largely ossified anteriorly. 

Palatine bones free from other elements except pterygoids. 

No symphysis mandibuli. 

Sternal and pelvic arches wanting ; no limbs except rarely rudiments posteriorly ; no 

Vertebra? united by double articulation ; neural arches continuous with centra ; no chev- 
ron bones. 

Circulatory and Nervous Systems, in important features as Lacertilia. 



Leidy says with reference to the species here described, " They have an affinity to 
Ichthyosaurus and Eosaurus, nor am I prepared to prove that they do not belong to one 
of these." 

C7ionespondylus yrandis, Leidy. Proc. Acad. Nat. Sci., Philada., 1868 — 178. 

Humboldt Co., Nevada. 




This genus, as suggested by Huxley, may be the type of a peculiar division of the 
Batrachia. There appears to be some probability of this being found to be the case, though 
present evidence is in favor of Prof. Marsh's location here. 

Amer. Jour. Science, xxxiv. 1S62, 1 Tab. I, II. 

Coal measures : Joggins of Nova Scotia. 


This great order of Reptilia corresponds with the Monimostylica of Midler, without 
the Testudinata. The latter differ too much in the vertebral and sternal structure to be 
retained in it. 

The important feature which characterizes the order, the close sutural attachment of 
the quadrate bone, may be readily understood by comparison of the accompanying figures 
of Nothosaurus from the Muschelkalk of Germany, and Mecistops intermedins Graves,f 
recent, from the Orinoco, with the plate of Clidastes propython, at the end of the volume. 

The order embraces that large series of forms which seem to be equidistant between 
all the extremes of the Reptilian type. It therefore is not a strictly homogenous group ; 
yet its subdivisions do not appear, with present knowledge, to be sufficiently marked, to 
render it proper to esteem them of equal value with the other orders here enumerated. 
This is a usual difficulty of classification ; Ave express it, and do not remove it, by admitting 
the existence of a protean type in a genus of species, a family of genera, a class of orders, 
etc., etc. The suborders are as follows : 

Limbs without flexible articulation ; natatory ; no femoral trochanters ; no sacrum. 
A procoracoid united with scapula ; a distinct episternum. 
Ribs single headed. 

# The following species have been described by Leidy, who refers them to Reptilia with doubt, and says they may- 
be fishes. As this point remains undecided, I can only allude to them here. 

Proceedings Acad. Nat. Sciences, Philada., 1858. — 178. 

? Triassic of Humbuldt Co., and of the Toiyabe Range, Nevada. 

? Triassic ; Humboldt, Nevada. 

f This cut is taken from the type specimen of Mecistops bathryliyncTius, in Mus. Academy. The Nothosaurus is 
the N. andriani or a nearly allied species. I am not quite positive that the number of alveoli on the maxillary bone 
is exactly correct. 



Fig. 3. 

Pig. 4. 


External nostrils posterior. 

Pubes entering acetabulum, transverse, united medially. 

Vertebrae with zygapophyses only. 

Ribs single-headed. Chevron bones present. 




Fig. 5. 

Fig. 6. 


Limbs ambulatory, no third trochanter. 

Sacrum of two vertebra 3 . 

No procoracoid or clavicle. 

Ribs mostly double-headed. 

External nostrils anterior. 

Pubes longitudinal, not entering acetabulum ; free distally. 

Zygapophyses only ; chevron bones 

Limbs ambulatory; a third trochanter on femur. 

Sacrum of two or three vertebra? ; acetabulum entire ; pubes united. 

Ribs double-headed. 

External nostrils posterior. 

Zygapophyses only and chevron bones. 


Limbs ambulatory or prehensile. 

Ilium horizontal, supporting a long sacrum of five or six vertebrae, the anterior derived 

from the lumbar series. 
The acetabulum thrown forwards, and not complete, but perforate. 


Ischium long longitudinal, posterior, supporting the pubis in front on a process. 

Ribs free, double headed. 

Neural arches united by suture ; chevron bones present. 


Limbs ambulatory. 

External nostrils anterior. 

Inferior pelvic elements in contact transversely, acetabulum imperforate. 

Sacrum of six vertebras. 

Neural arches attached by suture. 

Premaxillary single or double ; 

Teeth wanting or represented by a pair of tusks, or canines. 

No columella. anomodontia. 

Limbs ambulatory. 

External nostrils anterior. 

Inferior pelvic elements in contact transversely. 

Sacrum of two vertebra?. 

A columella. 

Clavicle, episternum and xiphisternum present, united. 

Chevron bones. rhynchocephalia. 

The important modification in the mode of articulation of the quadrate bone, which 
characterizes this order has been overlooked in most of the systematic arrangements of 
the extinct and living Reptilia. The subordinate forms differ in important points, but the 
groups Sauropterygia, Thecodontia, and Crocodilia, appear to be related by a close bond, 
as for example the marine, the terrestrial, the Sphargid, and the Pleurodire tortoises. The 
extremities are modified for all modes of progression, except that of flight, in both ; while 
as much gradation between these types is seen in one as in the other. In the characters 
of the anterior and posterior nasal openings, there is a great range in these types, but 
the transitions in these respects occur successively from Crocodilus to Teleosaurus,* to 
Belodon, to Plesiosaurus and Nothosaurus. 

An important definitive character is found in several types of the Archosauria. The 
pterygoid bones are prolonged anteriorly between the palatines, and frequently as far as 
the vomer, completely separating the palatines. The latter then he exterior to the 
pterygoids and between them and the maxillaries. When they bear teeth the latter 
form a series within and parallel to that of the maxillary bone. 

This structure occurs in Sauropterygia, as Nothosaurus, (see fig. 4.) and in Ehynchoce- 

*See Huxley on relations of Plesiosaurus to Teleosaurus, Journ. Geol. Soc. Lond. 


phalia (Sphenodon Hyperodapedon.) I have not observed it in any of the Crocodilia, 
but the palatal roof of several genera of this order is unknown. No such structure is 
known among the Streptostylicate Reptilia. 

This order appears first in time, in its Sauropterygian and Thecodontian representatives 
in the Trias, and in the genus Protorosaurus Meyer, even in the Kupferschiefer, a member 
of the Permian. At the same time it is the only one of the characteristically extinct 
types, which remains to the present day. This it does in the lihynchocephalia and 
especially the Crocodilia, the most persistent reptilian type. It must also be observed 
that the Trias of Scotland has yielded a type (Leptopleurum), which Huxley refers to 
the Lacertilia. 


This genus is established on a series of vertebra? with portions of pelvic arch and pos- 
terior extremity, discovered in the upper Cretaceous of Kansas by W. E. "Webb, Superin- 
tendent of the land office in Topeka, Kansas. The point at which the remains were 
found is about five miles west of Fort Wallace on the plains near the Smoky Hill river, 
Kansas, in a yellow Cretaceous limestone. 

The animal thus indicated is of interest in American vertebrate palaeontology, as the 
first true Plesiosauroid discovered within our limits. That its affinities are nearer to 
Plesiosaurus than to Elasmosaurus will be apparent from the following description. 

There are wholes or portions of twenty-one vertebra;, of which but two retain their 
neural arches, and six are represented by neural arches only. Four centra may be referred 
to the caudal series, the remainder to the dorsal ; there is nothing to indicate the characters 
of the cervical vertebra?. All of these vertebrae, except the distal caudals, are remarkable 
for their short anteroposterior diameter and deeply concave articular faces. This concavity 
is not however of an open conic form, as in Ichthyosaurus, but is flattened at the fundus 
thus exhibiting a small slightly disciform area. The usual pair of venous foramina appears 
on the under side of the centum. The neural arch is continuous with the latter, and 
exhibits no trace of connecting suture. The diapophyses arise from the neural arch in all 
the dorsals ; they are compressed and vertical in section. The arch is of course narrow 
anteroposteriorly, and presents a pair of moderately prominent zygapophyses in each 
direction, the posterior as usual articulating downwards, the anterior upwards. On some 
of the vertebrse they become closely approximated. The neural spines are narrow antero- 
posteriorly, but much stouter transversely than in Elasmosaurus ; they are strongly grooved 
at the base, both anteriorly and posteriorly, most so posteriorly. 


The caudal vertebras are anteriorly quite as large as the dorsals. Two anterior caudals 
present on the latero-inferior part of the posterior margin, a pair of widely separated artic- 
ular surfaces for chevron bones. A portion of one of the latter remains ; it is narrow and 
sub-cylindric at the base. The diapophyses are situated on the upper part of the centrum, 
and are continuous with it, and without trace of suture. There are two distal cervicals, 
which are much smaller than the preceding. They are solidly coossified and have been 
broken from one anterior to them, with which they have been also anchylosed. Processes 
in the position of diapophyses have disappeared, while a strong infero-lateral process 
projects from the middle of each, similar in position to the parapophyses (or whatever 
they may be) of the Elasmosaurus. These processes are decurved and much thickened 
and rugose ; they may be described as more or less elongate conic. The neural canal of 
these vertebrae is well marked, though small. The coossification of cervical vertebrae is a 
remarkable character, and very unusual. It does not seem probable that these specimens 
represent a diseased condition, since they are symmetrical, and the inferior surface and for- 
amina are unaffected. The rugosity is much that of a ligamentous articulation. Their 
size indicates a remarkably slender neck as in Plesiosaurus, but even more so, and perhaps 
as elongate as in Elasmosaurus. 

That the portions of an extremity alluded to, belong to the posterior, is rendered prob- 
able by the presence of part of an ilium, and by the fact that the portions of the vertebral 
column secured, are chiefly median and posterior. The fragments consist of the extremity 
of the femur, the tibia, several tarsal bones, and numerous phalanges. The whole limb is 
of great size compared with that of the vertebral column, and indicates powerful natatory 
capacity in its possessor. What the relative length of the femur may be, cannot be ascer- 
tained, as the proximal portion is wanting, but if it were like the tibia, it was characterized 
by stoutness rather than by length. The portion remaining is flattened, and presents 
distally two distinct articular faces for ulna and radius, instead of the uniformly convex 
outline characteristic of most of the species of Plesiosaurus. The tibia is broader than 
long, and not emarginate externally. The fibula is wanting. One of the tarsal bones is a 
flat unequally hexagonal disc, of less thickness than the tibia and the tarsals which appear 
to connect with it. One of the latter is transverse parallelogrammic, with three faces of 
broad plane articulations and the outer rounded in section. Another tarsal or metatarsal 
is a parallelopipedon, except that one extremity presents two faces meeting at a right 
angle. Another is similar, but oblique, i. e., rhombic in section; one of the longitudinal 
angles is also prolonged. 

Of the phalanges there are individuals from three series. Portions of flat bones, 
perhaps, belonging to the pelvic arch, indicate, as do all the other pieces, that the bony 
structure in Polycotylus is more massive than in Elasmosaurus, if the only known species 


has not attained such huge dimensions as some of the latter. These fragments do not 
throw much light on the structure of the pelvic arch. 

The structure of the bones is, like that in the order generally, of the coarsest descrip- 
tion. There are no medullary cavities, but the medullary cells are large, and extended 
everywhere in the direction of the axis of each bone. 

The characters which separate this genus from Plesiosaurus may be derived from the 
preceding as follows : 

First ; the deeply biconcave, and very short vertebral centra. 

Second ; the tibia broader than long, resembling those of Ichthyosaurus. 

Third; the coalescence and depression of some of the cervicals. 

Fourth ; the continuity of the neural arches. 

Fifth ; the continuity of the diapophyses of the caudals. 

The only genus with which this genus compares nearly, is the Thaumatosaurus of 
Meyer. This is known but by a few fragments, and of these, but few are present in the 
Kansas animal. The character on which I rely at present to distinguish them, is the 
much less concavity of the dorsal vertebrae in Thaumatosaurus. This is however, not 
entirely satisfactory. Thaumatosaurus oolithicus Meyer is from the lower oolite of South 

The bones are thoroughly mineralized, and the adherent matrix is a light yellow 
chalky limestone, similar to that which yielded the fine fragments of the Macrosaurus 
proriger. This, Dr. Leconte informs me, is probably Meek and Hayden's upper Cretaceous 
No. 3, and is a higher horizon than that near Fort Wallace from which Dr. Turner 
procured the Elasmosaurus platyurus. The specimens were all taken out under the 
direction of W. E.Webb, of Topeka, from the same spot; from every point of view there 
is reason to believe that they belong to the same animal. 


The anterior dorsal vertebrae have the centra slightly compressed or vertically oval, while the posterior are more 
rounded. The anterior caudals appear to have been round or nearly so; they are somewhat distorted by pressure. 
The sides of the centrum are slighly concave in the longitudinal direction; below, there is no carina, but at least two 
venous foramina. There is another large foramen on the side of the centrum, usually not far from the neural arch ; 
there are usually other smaller foramina below this. The bases of the diap'ophyses are longitudinally grooved 
behind, and separate a concavity of the arch in front of them from one behind. In the most median, the most 
elevated diapophysis stands about equally on the neurapophysis and the neural spine above it. The diapophysis 
are vertically compressed, and the costal articulation of the only one preserved, is in the same plane. The margins 
of the external surfaces are not coarsely striate as in many Sauropterygia. The venous foramina of the distal 
coossified cervicals are in pairs, and of a large size. In the proximal caudals the diapophyses are above the middle of 
the sides of the centra. In one the basis of a chevron is preserved. It is cylindric and striate. The zygapophysis 


on the hinder aspect of a dorsal has a disciform articular surface directed outwards and downwards : the prominence 
of its upper face is continuous with the lateral ridge of the neural spine. The anterior uplooking surface is equally 
small and little divergent. 


Vertical diameter centrum dorsal, 3.42 

Transverse " " " 2.7 

Antero-posterior diameter centrum dorsal, (helow,) 1.85 

Vertical diameter centrum dorsal, (poster,) 2.98 

Transverse " " " 2.9 

" " neural canal, .80 

Longitudinal diameter base neural spine, 1.22 

" " " diapophysis 1.2 

Length between extremities zygapophyses, (dorsal,) 2.26 

Depth of cup of vertebra?, .63 

Length centrum anterior caudal, 1 .73 

Distance between bases chevron bone, (caudal,) 2.58 

Length two coossified caudals, 2.3 

Width anterior in front, 1.7 

Depth " " .9 

It may be observed the anterior caudals have a nearly round articular extremity ; one of them is a little wider 
than high, but they are too much distorted to furnish reliable measurements. 

The portion of ilium preserved is an extremity. It is flat on one side and convex on the other. The shaft is 
solid. The articular extremity is oblique, and presents a truncate extremity, which is at right angles to a short 
recurved margin, which has been an insertion or articulation ; the flat surface is rugose distally. Long diameter of 
extremity, 2 in. .75 ; of shaft, 1.9 in. The articular faces of the extremity of the femur are at an open angle with 
each other, and are strongly concave in transverse section. The femur is here very flat, with narrow margins: it 
becomes stouter with diminishing width. Distally the surface is marked by grooves and small foramina. What may 
be tibia is the basal frustrum of a wedge ; the articular faces broad, the outer margin narrowed ; the faces slightly 
concave. The inner margin is shorter than the outer, and the distal part of it presents a broad articular face. Some 
of the tarsal bones have been already described. There are thirteen metatarsals and phalanges. They are of stout 
proportions and are considerably constricted medially. Those of one series are square in section ; those of another, 
transverse; those of the third transverse with one edge thinned or acuminate in section. Some of each form are 
more elongate than others. 


Width femur at extremity, (restored, ) 8. 

Depth " " (median,) 1.3 

Width " four inches from extremity, 6. 

Thickness femur " " " 1.95 

Width tibia, 3.88 

Length externally, 2.6 

Width tarsi tibiale, 2.48 

Thickness " " 1.52 

Length parallelopiped phalange, 1.56 

Width " " 1.2 

Thickness " " 1.2 

" depressed " 1. 

Width " " 1.4 

Length " " 1.9 



These powerful extremital pieces indicate a body to be propelled, of not less than usual proportions. If this he 
the case the number of dorsal vertebrae is considerably greater than in the species of this order in general, and 
approaching more the Ichthyosauri. I do not intend to suggest any affinity between the latter and the present genus, 
as none exists. What the extent of cervical vertebrae may have been is uncertain. The eaudals have probably been 
numerous, though not probably so extended as in Elasmosaurus. 

The size of the species can be approximately estimated from the proportions furnished by Owen (Reptiles of the 
Liassic Formations) for Plesiosaurus rostratus. The skeleton of this species measures 11 feet 8 inches, and the 
dorsal vertebras are of less vertical and equal transverse diameter compared with those of the present Saurian. We 
may therefore suppose that the latter exceeded the former in dimensions. 

William E. Webb of Topeka discovered the specimens on which this species rests, and liberally forwarded them 
to me for examination and description. 

Ischyrotherium Leidy. Trans. Amer. Philos. Soc , 1800, 150. 

This genus has been referred by Leidy to the Mammalia, and to the order Sirenia, 
with doubt. Having access to a part of the remains on which it was established, I have 
arrived at the conviction that it really represents an aquatic Saurian more or less distantly 
related to Plesiosaurus. My reasons for regarding it as Reptilian and not Mammalian 
are : first, the articulation of the neural arch with the centrum ; second, the absence of 
epiphyses ; third, the absence of articulation for the head of the rib on the centrum ; 
fourth, the lack of tubercuhun on the ribs. 

With respect to the first of these characters, it may be remarked that it never exists 
in mature Mammalia, and disappears at an early period of the development of all, except 
in certain seals and the Echidna, where the consolidation of the neural arch is a little 
delayed. As to the epiphyses, there is no trace of their suture to be found on fractured 
surfaces, supposing their existence to be indicated by the series of foramina extending on 
the inferior surface of the centrum near each articular extremity. These foramina 
are, I believe, merely the ruptured coarse cells, which can be found near the articular faces 
in the vertebrae in all Sauropterygia. They are unusually small in this genus, appropri- 
ately to the denser structure of the bones as compared with other sea saurians. The 
articulation of the rib takes place at the extremity of a long diapophysis, and there only, 
there being no pit for the capitulum. This does not occur in Mammalia, but is highly 
characteristic of the lower groups of the Reptilia, especially the Sauropterygia. The lum- 
bar series in Cetacea presents a somewhat similar structure. The vertebrae in question are 
referred by Leidy to this position, but they are clearly median dorsals, from the elevated 
position and length of the diapophyses. The simple form of the ribs, some of which are 
from the same part of the column, is quite unknown among Mammalia. 

There are other significant characters of less value, which point to the saurian affini- 
ties of this genus, and confirm the preceding. These are the very small size of the neural 
canal, the cylindric or thickened form of the neural arch, and the strong venous foramina 


penetrating the centrum, which, though not wanting in such mammals as BasilosaurusTand 
its allies, are neither so numerous nor situate so near the neural arch as here. (See Leidy's 
fig. 11.) 

The ribs, as remarked by Dr. Leidy, are remarkably dense, lie observes that " from 
the solidity of structure and cylindroid form of the ribs, I suspect Ischyrotherium to be 
more nearly allied to the Manatee than to any other animal." This consideration does 
not affect the affinities here accepted as true. The structure is remarkable, and differs 
from that of Manatus and Squalodon much as Reptiles do from Mammals, in its homoge- 
neity, or when interruption of the same occurs, in its appearance as irregularly disposed 
cells, and in the lack of a concentric structure of any kind. In the Mammalian genera in 
question, as well as in Basilosaurus* this concentric structure is eccentric in relation to 
the circumference of the rib. 

The genus Mesosaurus Gervais, according to plate XLII of his Zoologie et Pala?ontol- 
ogie Generale (the letter press has not yet reached me), presents ribs of similar form to 
those of Ischyrosaurus, but whether of similar structure I cannot ascertain. 

Leidy concludes his description of this genus with the following remarks : " Although 
I have supposed the remains * * to indicate * * an animal allied 
to the Manatee, * * I have suspected that they have belonged to an aquatic 
reptile unlike any known." * * Entertaining the opinions that I do respecting 
the relations of the genus, I have thought that the name applied by Leidy, which is appro- 
priate only to a mammal, should be changed. I therefore call it Ischyrosaurus, maintain- 
ing the first etymology so far as practicable. 

I refer it to the Sauropterygia, as the parts resemble Plesiosaurus more nearly than 
those of any other American genus. The density of the osseous structure and the cvlin- 
dric form of the ribs, will distinguish it from Plesiosaurus ; from Polycotylus the form of 
the vertebra? separates it at once. 

I suppose that this type may have been of estuary habits, and took its food in proxim- 
ity to land. The density of the bones is not known in, nor is it appropriate to, animals 
of the open ocean. The presence of Hadrosaurus (Thespesius) occidentalis in the same 
beds, is further evidence of the proximity of land. 


Ischyrotherium antiquum, Leidy. Proc. Ac. Nat. Soi., Phila., VIII, p. 89. Trans. Amer. Philos. Soc. 1SG0, 150 
Tab. X, figs. 8-17. 

The dorsal vertebrae of this species present plane articular extremities. The centrum is not constricted medially, 
but presents a shallow concavity round its median portions. The sutural articulation of the neural arch is shallow, 
sub-ovate, and extends throughout the length of the centrum. The diapophyses are compressed cylindric. The 

* See Owen on this genus. 


articular face is a transverse oval. The size of the animal is similar to that of the Plesiosauri of medium dimensions, 
perhaps ten feet in length, admitting elongate neck and tail, of which there is no evidence. 

Position.— Bed Q. Hayden's Section of Great Lignite basin of Nebraska. (Trans. Am. Philos. Soc, 1860,135.) 
perhaps of the Cretaceous age; from the Moreau River. 

1 refer the following species to this genus provisionally, and with doubt. 


This reptile is represented by but few remains, which are in the private collection of Dr. Samuel Lockwood, of 
Monmouth County, N. J. A single dorsal vertebra, which he kindly lent me for description, presents characters which 
are so marked when compared with other marine Sauria as to require notice. 

The centrum is of the general form of Plesiosaurus and Cimoliasaurus, and the arch has a sutural attachment as 
in the former. The suture is the surface of a sub-round pit, almost like that of Ichthyosaurus, and not like that 
typical of Plesiosaurus, or the young of Cimaliosaurus magnus. In the latter the suture is an oval concavity which 
extends throughout the length of the centrum. The pit in this species measures little more than one-third the 
length of the centrum. The floor of the neural canal is quite flat. The sides of the centrum are strongly and 
regularly concave, rather less strongly below than laterally. The margins flare regularly, and are not striate 
grooved or ribbed as in many species. There is a strong venous foramen a short distance below the neural arch and 
two medially below. 

The species is further characterized by the regularly concave articular faces, without median plane or prominent 
portion, as in Cimoliosaurus species. They are more concave than those of the Elasmosauri also. The form of the 
surface is entirely circular. 

Width articular surface, 
Depth " " 

Width pit neural arch, 
Length centrum, 

This species I have dedicated to its discoverer, Dr. Lockwood, who has contributed in various ways to the 
progress of Natural Science. 

It is the earliest sea saurian from this country, as it was derived from the clays which underlie the lower green 
sand bed. It was dug from a brick clay pit near Matteawan, Monmouth County, N. J. 


Cimoliasaurus and Discosaurus, Leidy. Proceed. Academy Nat. Sci., Pkila., 1851, 325 — 1854, 72, tab. ii, figs. 4, 5, 
G, and 1851, 326; Cretaceous Reptiles, 22 and 25, tabs. IV., V., VI. Brimosaurus Leidy, Pr. A. N. Sci., Phila., 1855, 472. 

This genus has been chiefly illustrated by Leidy, who has described remains of its 
species from the cretaceous deposits of many of the States east of the Mississippi. It has 
remained for the discovery of Elasmosaurus to prove that the two supposed genera named 
by Leidy, are really one, his supposed caudals of Discosaurtis* being really caudals of Cim- 

* This genus was originally proposed on two vertebra? from Georgia, and a vertebra from New Jersey described 
by Dekay. He afterwards added vertebra? from Alabama, Mississippi and New Jersey. Some of these were regarded 
as cervicals; they are, however, anterior caudals. N As Leidy observes, there are several species among them, and it 
may be, several genera, but as the genera cannot be distinguished by the caudal vertebra?, it appears to me that Dis- 
cosaurus cannot be preserved. While distinguishing the genus from Cimoliasaurus, Leidy adds, "The supposed cau- 
dals of Discosaurus I have suspected to be anterior cervicals, notwithstanding the apparent provision for the articula- 
tion of chevron bones. If all the vertebra? be viewed as belonging to one animal, they represent cervicals, dorsals and 
lumbars of Discosaurus; otherwise they represent a cervical and caudals of the latter, and dorsals and lumbars of Cim- 
oliasaurus. " In case of their identity, it may be observed, Leidy refers them all to Discosaurus. Cimoliasaurus was, 
however, proposed first. 

r n. 











oliasaurus, the supposed caudals of the latter proving to be its cervicals. Characters dis- 
tinguishing it from Plesiosaurus have never been pointed out, and it is here retained apart 
from it on the supposition that its scapular arch is constructed on the same principle as 
that of Elasmosaurus, a point, however, which has not been ascertained. 

This genus is not as well known as Elasmosaurus, owing to the fragmentary condition 
in which it is usually found. Its marked character is its short depressed cervical region, 
as compared with the excessively long and compressed one of Elasmosaurus. It also dif- 
fers from it in the apparent continuity of the series of diapophyses from the dorsal to the 
cervical series. In Elasmosaurus these processes are wanting on the anterior dorsals. 
They are very elongate on the other hand, on the posterior dorsals of Elasmosaurus ; in 
Cimoliasaurus we have as yet no evidence as to their length, as they are broken in our 

Fi<f. 13. 

Fig. 14. 

Fig. 10. 

■% mp!«i»- 


The rapid diminution in dimensions of the cervical series in Cimoliasaurus indicates 
a short neck, and far less slender general form. Leidy suggests from the absence 
of sacral characters, that posterior limbs have been probably wanting in this genus : the 
same vertebral characters are seen in Elasmosaurus, but it has a large pelvic and scapular 
arches ; the presence of limbs in it cannot be doubted. The femur of Cimoliasaurus is 
described below, and is the only limb bone yet assignable to a species of this genus. It 
resembles that of Plesiosaurus. It is thicker and shorter however than in any species of 
the latter genus, and is quite short. The distal extremity is thick, and presents pits for 
the attachment of the articular cartilage ; the faces for both ulna and radius are extensive, 
and indicate a large manus and elongate limb. The rotundity of the head indicates ex- 
tensive rotation ; and we may be satisfied that the animals of this genus were furnished 



with powerful propelling flippers. The preceding cut illustrates its form and size in rela- 
tion to the posterior dorsals from nearly the same position in the C. magnus and Elasmo- 
saurus platyurus. 

The general characters of the cervical and dorsal series are very similar to those of 
Elasmosaurus, but they all exhibit considerably larger neural canals. In the immature 
individual, the neural arch of the dorsal vertebra? is not coossified, but is separated by 
suture as in Plesiosaurus. 

That there are several species of this genus is suggested by Leidy, and seems probable 
to the writer. As one of these has been already named, the characters of those which 
appear distinct may be pointed out. 

Anterior caudals, articular faces with rounded margins ; antero-posterior diameter 
greater, 2 in., width, 2 in. 7 1. Pit of diapophysis 1 in. 3 1. 


Anterior caudals, articular faces with acute marginal angle, antero-posteriorly shorter 
1 in. 7 1. by 2 in. () 1. in width; pit 111. Cervical with straight sides and broader form; 
width 31.2 1. by 24.5 long, the Miapophysis narrow and stout. 


Anterior dorsals shorter and higher than in C. magnus, the posterior cervicals, there- 
fore shorter than in the same ; diapophysis of first dorsal longer. 


Posterior cervical with neural canal as large as C. magnus, but centrum four times as 
large, and a strong longitudinal ridge half way between pleurapophysis and neural arch, 
giving pentagonal section : 45 1. long by 52 1. wide ; hence longer. 



Discosaurus Leidy, Proc. Acad. N. Sci., 1851, 326. Cretaceous Reptiles, N. A., 22. Plesiosaurus, DeKay Ann. 
Lye, N. Y., 1828, 165, Tab. 

If the vertebras from Alabama from Jos. Jones, described by Leidy in the Cretaceous 
Reptiles as No. 1, are typical of this species, they present certain pecidiarities which distin- 
guish them from those of an individual of C. magnus which I describe below ; perhaps 
the species are distinct. 

Cretaceous Alabama, ? Mississippi and ?New Jersey. 











Pr. A. N. S., Phila., 1851, 335, 1854, 72. Cretaceous Rept. N. A. 25, tab. 00. 

This species has hitherto been known from vertebra} only. In connection with vertebrae of this species, I pro- 
cared a long bone which has a near resemblance to the femur of Plesiosaurus. It indicates a paddle for motion in the 
water, as has already been mentioned. 

The distal breadth is equal to If the length. It is distal compressed, but thick and with rounded margins. 
The proximal portion is slightly reverted to the condyle, and compressed nearly at right angles to the distal extremity. 
The condyle is flattened convex and oval in circumference. The tibial and fibular articular faces form a strong angle 
with each other, and are pitted rugose for the cartilaginous articulation. 

Distal breadth, 
Breadth at neck, 
Diagonal across condyle. 

It is seen, therefore, that this bone is remarkably robust, much more so than in the Plesiosauri of adult age. 
That the individual to which it pertained is not mature, appears from the dorsals accompanying, in which the neural 
arch is not fully coossified to the centrum. We can regard the species as a robust and powerful animal, in which bulk 
is more prominent than length. 

Anterior dorsal, length centrum, 

Width do., 

Depth do., 

Length articulation for neurapophysis, 

Width do. do., 

The centrum is much constricted medially and the diapophyses are given oft* from the neurapophyses, the lower 
margin corresponding with that of the bottom of the neural canal. This specimen is from Barnesboro, and was 
submitted to me by Prof. Cook, State Geologist. 

Locality: the Cretaceous Green Sand of New Jersey; upper bed. 


Brimosaurus grandis, Leidy, Proceed. Ac. Nat. Sci., 1854, 72; tab. I., II. 

From Cretaceous of Clark County, Arkansas (near Greenville). 

I have not seen any part of this, the largest species. It is, from Leidy's figures and description, distinguished 
by the relatively greater width and height of its vertebrae, and has been therefore a shorter and more massive animal 
than its congeners. As nothing beyond Leidy's description is known of it, I append the latter. 

It was represented by vertebrae from near Greenville, Clark County, Arkansas. They had been kindly loaned by 
W. T. Roberts, an agent of the Arkansas Mining Company, who had discovered them with numerous others. Dr. 
L. stated that, in his visit to St. Louis, Mr. Alb. Koch, the industrious collector of fossil remains, had exhibited to 
him a collection of bones from the same State, and apparently of the same animal, which he was on the eve of 
sending to Berlin. The specimens are remarkable for the robust transverse processess, which project laterally 
from the lower part of the body, and terminate in a large facet for the articulation of a rib. The bodies are 
cylindroid, and are terminated by slightly concave or nearly flat articular surfaces. The sides of the body are moder- 
ately concave, and have an acute margin at the articular surfaces. On each side of a median prominence of the under 
side of the body a large vascular foramen exists. These vertebrae resemble those of Cimoliasaurus magaus from The 














green saud of New Jersey, described previously in the Proceedings of the Academy of Natural Sciences, but in that 
the large transverse process is cylindrical, while it is compressed cylindroid in the Ark. saurian, and probably the 
latter belongs to a distinct genus, for which the name Brimosaurus is proposed. The bones are imbedded in a hard 
limestone with mollusca, and they probably belong to the cretaceous or to the eocene period. One of the most perfect 
of the vertebras presents the following measurements : 

Length of the body, 3jj 

Depth articular surfaces, 5 

Breadth do. do., G 

Length of the neural arch, 3 

Dr. Leidy proposes to consider this species as the type of a genus distinct from the present, because its diapophyses 
are compressed in section, while those of Cimoliasaurus are cylindroid. I think this difference depends on the posi- 
tion in the vertebral column. These processes descend on the anterior part of the column and become more flattened, 
until they resemble diapophyses of ordinary cervicals. This vertebra therefore was an anterior dorsal. 


Leconte's notes on Geology of the route of the Union Pacific Railroad, 1868, p. 08. Cope, Proceed. Acad. Nat. 
Sciences, 1868, p. 92. 

This genus has been more completely preserved to us than any other American repre- 
sentative of the order, and hence may be accepted as most clearly expressive of its char- 
acters. In the interpretation of these, however, considerable difficulty has been experi- 
enced, as the structure form appears, at first sight, to reverse to a remarkable degree, 
the usual proportions of known reptiles. 

The determination of the anterior extremity of the vertebral column has been rendered 
certain by the fortunate completeness of the cervical series, as the extraordinary length 
of the latter, equalling three times that of the body, renders the most careful scrutiny 

The neural arches are every where continuous with the centra, without sign of suture, 
and are externally plane. The neural canal is exceedingly small for the size of the 
vertebrae, especially on the lumbars and caudals. 

The dorsal vertebras are remarkable from the fact that the diapophyses disappear on 
the anterior part of the series, and gradually diminish in length from behind forwards to 
the point of disappearance. On the median and posterior parts of the series they are 
very elongate, and rise for a short distance from the basis of the neural arch. Ante- 
riorly, they descend and shorten, and finally remain only as the slightly elevated borders 
of rib-pits. Throughout the whole of the anterior portion of the column to the cervicals, 
the neural spines are of great elevation, and of such antero-posterior extent as to be 
nearly continuous. 

The cervical vertebra? are not only more numerous, but become anteriorly much smal- 
ler and more attenuated than in its allies of the same family. They are remarkably com- 


pressed, the centra much longer than deep, and deeper than wide, and with smooth con- 
cave sides. 

The ribs of the anterior cervico-dorsal region are inserted directly in the vertically 
oval pits of the centrum. Immediately at the point where these cease, thin transverse 
processes appear to arise from the lower edges of the rib pits. They form a continuous 
series with the ribs, and soon rise from the plane of the lower face of the centrum, and 
are directed obliquely downwards. At the end of the cervical series they are directed 
nearly vertically downwards. The number of these vertebrae is very great, the anterior 
diminishing to a very small size, the whole measuring a little more than half the total 

Most of the cervicals possess two venous foramina below ; the dorsals two, and most 
of the caudals one. 

The resemblance of the caudals to the usual type of Plesiosaurus, is seen in the fact 
that each bears near its posterior articular aspect, on the inferior face, a pair of articular 
surfaces, for chevron bones. Similar vertebrae had been described by Leidy as the caudals 
of a genus he called Discosaurus; the study of the present genus shows that they are 
really of the caudals of the allied genus Cimoliasaurus. 

The ribs are simple headed ; the abdominal ribs seen in Plesiosaurus are possibly 
wanting, as none were found by the discoverer of the fossil, after a careful search. 

The end of the muzzle, with symphysis mandibuli, was preserved. This is flat, the 
symphysis rather short, the premaxillary grooved at the intervals between the dental alve- 
oli. The teeth are deeply implanted, with small pulp cavity, are cylindric and furnished 
with nearly straight elongate conic crowns, which are minutely but sharply striate to the 
tip ; the ridges, straight, continuous. There are no indications of nostrils, so that these 
were probably posterior and near the orbits, as in Plesiosaurus. 

The pelvic arch is more extended than the scapular, and strongly resembles the pelvic 
arch of other Plesiosauridse. The scapular arch is peculiar ; the claviculi are broad flat 
bones resembling the pubes of certain tortoises, while the coracoids are much like the 
coracoids of Plesiosaurus. 

The scapular arch is remarkable for the resemblance of coracoids to those of Plesio- 
saurus. The clavicles have a greater transverse extent than the former, and have a very 
extensive line of union medially, and a narrow posterior prolongation which meets a simi- 
lar anterior one of the coracoids, separating the intervening foramina. They appear to 
form about one third of the walls of the glenoid cavity, and have a constricted base as in 
some Plesiosauria, applied to the extremity of the coracoid. The form of the glenoid 
cavity cannot be readily ascertained from the absence of the scapula. What we have ol 



it would suggest the existence of a fore limb, of comparatively little power, though no 
remains of such have been found. The acetabulum is smaller than the glenoid cavity ; 
this point, with the obvious source of propulsive power in the tail, renders it probable that 
the posterior limbs were the weaker of the two, if any existed. But there is no trace of 
sacrum nor of any modified diapophyses for support of an ilium. 

The ischia are flat, subtriangular bones with a long median line of junction, and 
communicating anteriorly with the posterior prolongation of the pubic plate. Their 
postero-exterior margins project well backwards. The pubes are broad plates, whose 
anterior margins diverge from each other. They are broader than the ischia, and form a 
broad shallow basin for the support of the viscera. The suture defining these elements 
is obliterated ; they are continuous, and form a weak inferior keel on the median line. 
A simple curved ilium has been preserved, for which there appears to be a smooth articu- 
lar surface on the pubis to which it was attached. 

The acetabular portions of these elements are flattened and furnished with convex 
articular surfaces. The supposed ilia are short curved bones, resembling that of Plesio- 
saurus latispinus Ow., or of some of the other species of that family. The shank is flattened 
cylindric, the distal extremity, dilated rounded and flattened. The proximal extremity 
sub-truncate, or truncate in two or three unequal planes, and with a median pit. It fits 
well when applied to a concavity on the articular surface of the pubis. The vertebrae 
above the pelvic arch were furnished with elongate, sub-cylindric diapophyses. 

The question as to the presence of posterior limhs remains unsolved. Dr. Turner 
having made a second careful search, and renewed excavations at the original locality, 
failed to find any bones which can be assigned to humerus, ulna, radius, carpus or phalanges, 
or similar elements of the hind limbs. This is the more remarkable, as the pelvic and 
scapular arches were further completed, and an additional number of ribs obtained. The 
inferior and lateral regions of the trunk, being then so abundantly discovered, what are 
we to think of the entire absence of the usually numerous elements of extremities'? The 
glenoid cavity is a rather angular cavity, and both were filled with solid argillaceous 
matrix. The acetabula are not cup-Uke, but merely exposures of the marrow, plane ex- 
tremities of the pubes and ischia ; they were covered with thin layers of gypsum ; the 
pieces of the ilia were found imbedded in the mass of matrix which occupied the pel- 
vic arch. 

The allied genus Cimoliasaurus Leidy possesses a femur, as described under head of 
that genus ; it is of shorter and thicker form than in most Plesiosauri. 

The skeleton so nearly complete would indicate no violent disturbance of the carcass; 
but if there were, it would be an unusual accident that all of the four limbs should have 
been removed from their sockets, without leaving even fragments. 


This genus is well distinguished from Plesiosaurus by the peculiarity of the scapular 
arch. The mesosternum appears to be coossified with the claviculi, and the three ele- 
ments form a broad breast-plate. If the claviculus was ever united with the scapula as in 
Plesiosaurus, no evidence of it can be seen in the specimen. Both the clavicular and me- 
sosternal elements are broader and more extended anteriorly. 

The American genera of Elasmosauridae may be compared as follows : 

Posterior cervical vertebrae without diapophyses: cervicals longer, compressed, neck 

very elongate. 


Posterior cervical vertebrae with diapophyses : cervicals quadrate, shorter, depressed, 
rapidly diminishing in size, hence the neck shorter. 


Prof. Owen figures and describes (Reptiles of the Cretaceous, Palaeontogr. Soc.) a 
vertebra which very closely resembles the cervical of Elasmosaurus. He considers it to 
be the cervical of a peculiar Plesiosaurus, which he calls P. constrictus, remarking, at 
the same time, its remarkably inferior pleurapophyses. This I believe to be a species of 
Elasmosaurus or an ally, and to be called for the present Elasmosaurus constrictus. 


Leconte's Notes loo. cit. Proceed. Acad Nat. Sci., 1868, 1. c. 92. 
Discosaurua carinatus, Cope. Leconte's Notes, 1. c. 

This, after Mosasaurus the most elongate of the sea saurians yet discovered, is represented by a more than 
usually complete skeleton in the Museum of the Academy of Natural Sciences in this city. It was found by Dr. 
Theophilus H. Turner, the physician of the garrison at Fort Wallace, a point situated 300 miles westward from 
Leavenworth on the Missouri river, and some distance north from the Smoky Hill Fork of the Platte river. Portions 
of two vertebras presented by him to Dr. Leconte when on his geological tour in the interest of the IT. S. Pacific 
Railroad Company, were brought by the latter gentleman to the Academy, and indicated to the writer the existence 
of an unknown Plesiosauroid reptile. Subsequent correspondence with Dr. Turner resulted in his employing a 
number of men, who engaged in excavations, and succeeded in obtaining a large part of the monster. Its vertebras 
were found to be almost continuous, except a vacancy of some four feet in the interior dorsal region. They formed 
a curved line, a considerable part of whose convexity was visible on the side of a bluff of clay shale rock, with seams 
and crystals of gypsum. The bones were all coated with a thin layer of gypsum, and in some places their dense layer 
had been destroyed by conversion into sulphate of lime. 

The scapular arch was found in large part adhering to the bodies and neural spines of a series of the anterior dor- 
sal vertebras, and was detached from it at the Academy. The pelvic arch had been slightly crushed, and the lumbo- 
sacral vertebras forced into contact with the ischia, where they remain. A broken extremity of the supposed ilium 
was forced into the matrix which supports the ischia. Many of the dorsal and caudal vertebrae were sent, and remain 
in continuous masses, so that the succession is readily traced, and the true relations of the extremities preserved. 

In removing the matrix from beneath' the vertebras, scales and teeth of some six species of Physoclyst and 
Physostomous fishes were found, including an Enchodus and a Sphyraena, the latter indicating a new species, which 
I have called S. carinata. These animals had doubtless been the food of the Elasmosaurus. 


The end of the muzzle was broken from a part or the whole of the cranium, which has not been rediscovered, 
though Dr. Turner has made careful search. It was found in front of the vertebra? here regarded as cervical, at some 
distance from them. 

The whole skeleton has been under considerable pressure, so that most of the ribs have been pressed flat on the 
vertebra; the long parapophyses of the cervicals have most of them been fractured at their bases and compressed, 
those of opposite sides thus approaching more nearly in the form of chevron bones than they otherwise would have 
done. The proximal cervicals are obliquely flattened by the pressure; the other cervicals have the bodies naturally 
flat, with the articular surfaces much less so than the median portion. Some of the caudals are obliquely distorted. 

Description — Vertebra. — The neck may be safely assumed as a point of departure, as it consists of above sixty 
mostly continuous vertebra, which graduate to an atlas of very slender proportions. Most of them preserve more or 
less developed parapophyses. At the posterior extremity of this series, sixteen are perfectly continuous, and in this 
portion a great gradation in form is apparent. The anterior are narrow, compressed, and similar to the more distal 
cervicals in the elevated position of the lateral angle; the anterior are subqnadrate, thick, and with lower lateral rib, 
and stronger ? pleurapophysis. In these respects the latter resemble the dorsals which follow, towards what I believe 
to be the tail. Four anterior dorsals are in one mass (figured in plate 3); in this series the lateral angle first approach- 
ing, is finally lost in the margin of the rib-pit, the posterior thus resembling other dorsals. There can be so far little 
doubt that the anterior and posterior extremities of the masses are correctly interpreted. 

In a series of four anterior dorsals, which like the preceding, are in their original continuous mass, those of one 
extremity have centra rounded in section, with inferior rib-pits; those of the other have quadrate centra and elevated 
diapophyses; the former have the character of the first dorsals, the latter of the median dorsals. The posterior dor- 
sals and anterior caudals form in like manner a continuous series of eleven vertebra, fractured in four places. In 
them the diapophyses steadily descend, reaching the inferior plane in the last, thus with the reduction of the venous 
foramina to one, at the seventh, indicating the point of transition from dorsal to caudal series. The zygapophyses 
preserve the usual arrangement, but are much compressed, so that the posterior or down-looking, are confluent, and 
scarcely separated by an emargination. 

The neural spines at their bases have a slight posterior obliquity, and the superior portion leans strongly in the - 
anterior direction. The inferior limbs of the cervical pleurapophyses appear to be entirely wanting. The articular 
faces for the chevron bones are seen at the extremity of the inferior rib of the caudal. 

Of the cervicals there are both axis and atlas. Of the caudals, probably the distal half, at least, is lost. A single 
vertebra near the middle does not relate to either of those anterior or posterior to it. There are, therefore, at least 
four lost from that region also. 

There is a considerable interruption immediately anterior to the last dorsal vertebra. Three large vertebra, with 
long diapophyses, belonging here, were imbedded in the hard matrix which protected the pelvic arch. These 
are far from relating immediately to the vertebra preserved before and behind them. I estimate the number missing 
as follows: Seven of the fourteen dorsals preserved have more or less elongate diapophyses. In the Plesiosauri, 
vertebra of this character, are much more numerous ; in P. homalospondylus Owen gives seventeen. If we add 
ten to the series in the present species it will give the abdominal space between the adjacent margins of the o. o. pubis 
and coracoidea an extent equal to the length of the pelvic arch. This is relatively shorter than iu the Plesiosauri. 
Dr. Turner found that a space of " three or four" feet intervened between the two portions of the skeleton, which was 
otherwise continuous. I think ten an average number to represent safely the missing dorsals. 

From the cervical proximal regions probably three vertebra are missing from two interruptions. The remainder 
of the cervical series exhibits three interruptions. Most of the proximals have been broken medially, leaving the 
ticulations solid, an advantage in determining their continuity. Three vertebra and one-half are thus found to be 
missing in this region. 

The whole number of vertebra preserved and lost, with the relative lengths of each, may be stated as follows: 







Length In. 


Length In. 










































D orso-lumbars, 



This gives the total length to the animal of forty-three feet, two inches, which, increased by the amount taken 
up by intervertebral cartilages, will give roundly about forty-five feet. Of this, twenty-two feet must be reckoned to 

the neck. 


The cervical vertebrae from the sixty-sixth to the thirty-ninth are all longer than the dorsals; they commence four 
inches in length, increase to five, and diminish to four again. 

Length of sixty-third cervical, 

Depth articular face of the centrum, 


Total elevation ninth do., 

Length ninth caudal, 

Transverse diameter articular face, 

Vertical " articular face do.. 

Length head of rib, 

Width " 
" 'shaft 
Many of the ribs preserved have been pressed upon the vertebrae and crushed. 
The first dorsal is that vertebra which first presents a distinct articulation for a rib. 
much elevated above the centrum and are longest on the thirteenth (inserting seven supposed to be lost). Their forcn 
is stout and much depressed, and distally expanded. They diminish gradually, and on the third are represented by a 
longitudinal, slightly concave articular stirface, somewhat similar to those of the caudals. This surface is bounded 
above and below by a longitudinal, angulation; the superior is first distinct on the first, and bounds the articular sur- 
face last on the third. They give the transverse section of the posterior cervicals a pentagonal form; that of the an- 
terior dorsals is nearly circular. The latter are strongly constricted medially, and the articular faces are slightly con- 
cave. The external surface near the included angle is coarsely ridged, in conformity with coarse cellular texture of 
the spongy bone. The venous foramina gradually become more widely separated, approaching each other again on 
the posterior cervicals. On the dorsals they occupy the bottom of a more or less pronounced concavity. These con- 
cavities, on the posterior dorsals, are bounded externally by a strong obtuse longitudinal angulation, giving a quad- 
rate outline to the section of the centrum in this part of the series. 

The posterior cervicals are not readily distinguished from the anterior dorsals. In the latter the ribs appear to be 
present, of reduced length, judging from the smaller size of the remaining heads. The articular pits continue to de- 
scend till their lower marginal ridge is the inferior lateral angle of the vertebra. On such vertebras the inferior surface 
is flat. The neural spines ou dorsals and posterior cervicals are of great height as well as antero-posterior width, and 
they allow a very narrow interval between them. 

Antero-posterior diameter ?12th dorsal, 
Transverse diameter articular surface, 
Vertical do. do., 

Neural canal and spine (latter broken), 
Length diapophysis 12th dorsal, 
Width diapophysis at middle, 

The diapophyses are never 






































Anteroposterior diam. ?llth dorsal, 

Transverse posterior of articular face, 

Vertical do. do. do., 

Transverse posterior of neural canal, 

Transverse posterior of articular face, 3d dorsal, 

Elevation centrum, arch and spine, 2d dorsal, 

Elevation upper edge zygantrum 2d dorsal, 

Length zygantrum, upper edge, do., 

Length centrum, last cervical, 

Width centrum articular face cervical, 

Elevation neural arch and spine cervical, 

Antero-posterior width neural spine of cervical at zygapophysis, 
The cervical vertebra, are assumed to commence where the rib pits cease, and the continuous lateral processes 
commence. This point is ascertained with difficulty on the specimen. It is, however, perhaps the same point where 
the longitudinal lateral ridge leaves the upper margin of the rib pit ; and it was to the series of vertebrae which pass 
this point, the scapular bones, — the clavicle and coracoid were found attached. On the anterior dorsals the inferior 
margin of the rib pit is most prominent, and is finally produced in a flat thin process which is directed obliquely 
downwards. Both these and the posterior ribs are crushed on the centra and project obliquely below them; their mode 
of attachment is thus rendered rather obscure. A similar structure exists in the posterior cervicals of Cimoliasaurus, 
while on the anterior dorsals or where the rib-origins are on the lower plane, short thick diapophyses support the ribs. 
The proximal cervicals are remarkable for their compressed and elongate form. They are for a considerable distance 
longer than any dorsals. The lateral longitudinal ridge rises successively nearer to the neural arch and disappears. 
The articular surfaces are vertically oval, flattened above and below. The inferior faces are slightly grooved in line 
with the venous foramina. These vertebrae diminish in length, and after the posterior third of the series, materially 
in depth. They dimmish to terminal ones of very small size. In most the decurved '? pleurapophyses are broken near 
the base, but the basal portion of various lengths generally adheres. They are as wide as a rib; and scarcely half as 
thick. On some of the most anterior vertebrae, they are quite short and broad antero-posteriorly. They have much 
greater antero-posterior extent on the terminal than the proximal cervical centra, having a base five-sixths the length 
of the latter. The zygapophyses have relatively a larger size on these than any other vertebrae. In such the centrum 
is less compressed, though with concave sides, and with a section rather quadrate. 

The caudal vertebree have slightly concave articular surfaces, which are not bounded by groove or ridge. The 
neural arches have flat sides, and there is no longitudinal ridge above the diapophyses. The neural spines are 
elevated, the margins of those of the adjacent vertebrae close together. The diapophysis is very short and wide, 
terminating in a large oval concavity for the pleurapophyses. Each limb of the chevron bone is attached to an 
articular surface on the lower posterior face of the vertebra, at the extremity of a strong inferior ridge. These inferior 
ridges are rather close together, and distinguish the vertebrae from those of Cimoliasaurus magnus, where they are 
wanting. They are absent on the anterior seven of the caudal series. The diapophysis is nearer the anterior than the 
posterior face of the vertebra. The venous foramen is single and median, on all but the last six cervicals. 

Antero-posterior diameter of fourth caudal, 
Transverse do., 
Total elevation, 
Vertical diameter centrum, 
Anterior-posterior diam. diapophysial pit, 
do. do. third cervical, 

Transverse do. do., 

Heads of fourteen ribs are preserved, and a great number of shafts. The heads are simple, with elongate oval 
articular face. They are oblique in the narrow direction, and frequently in their length also ; the margins are 
somewhat everted. The extremities of the diapophyses of the larger dorsal vertebrae are transverse, some flattened, 


















the others more oval, the more anterior are sub-triangular, and the rib pits on the first dorsals are sub-round or 
vertically oval. Thus the heads of the ribs also vary. The shafts are all flat, probably more so from pressure. They 
are frequently curved in the direction of the compression, which suggests a vertical head. They however are probably 
more or less distorted, and the plane of compression changed. No well defined distal extremity of a rib can be made 
out, nor have anything like abdominal ribs been preserved. 

The scapular arch is remarkable for its large clavicles (or procoracoids). As preserved, the latter are quite con- 
vex downwards both antero-posteriorly and transversely, while the coracoids are equally concave in both directions. 

Fig. 7. 

Scapular Arch. 

The clavicles have a remarkable external flat projection, which is separated from the glenoid cavity by a deep sinus. 
The glenoid cavity is bounded by an elevated ridge, which sends a branch along the claviculo-coracoid suture to the 
precoracoid foramen. This foramen is relatively of small size, and is a longitudinal oval; the two are separated by 
an isthmus composed equally of processes of clavicle and coracoid. The coracoids are very thin except in a transverse 



portion, which extends across behind the precoracoid foramina; a strong elevated rib extends across the posterior face 
at this point. The outer margin of the coracoid is thickened, rounded and slightly concave. 

Greatest antero-posterior length scapular arch, 
" clavicle, 

" " " glenoid cavity, 

" " " precoracoid foramen, 

Transverse extent of clavicuh, 

" " coracoidea, 

From acetabulum to foramen, 

The form of the posterior margin of the coracoidea is unknown, and they are much broken on the inner margin. 
They may have been considerably longer than in the accompanying cut. 

The greater part of the pelvic arch appears to be preserved. From the obliquity of the median suture and 
from the form of the pubes as they are preserved on a large nodule of indurated clay, it is evident that they have 
formed a boat-shaped support to the abdominal viscera, with an obtuse keel on the median hue below. The following- 
diagram will explain the relation of its parts. 













Greatest antero-posterior length, 

Antero-posterior median length to notch of ischia, 
Length coracoids behind notch, 
Greatest width pubes, 
" " ischia, 








The anterior and lateral portions of the pubes are very thin, as are also the median posterior portions of the 
ischiadic plates. The pubic bones are thickest on the posterior margin; they present a downward projecting median 
convexity near the anterior end. Depth of the articular face, 2 in., 8 lin. 

The superior surface of this arch was brought to light by the exertions of my friends, B. Waterhouse Hawkins and 
Wm. M. Gabb, who removed a large mass of matrix which fortunately accompanied and protected it. This presents 
a transverse thickening extending across it, and continuous with the posterior margin of the clavicles. A median 
longitudinal thickening extends from this to the anterior emargination, embracing in its angle with the transverse, 
a shallow concavity. The posterior projection which is continuous .with the median part of the ischia, is strongly de- 
Hexed behind the transverse rib, and is continuous with the basin-like concavity formed by the united pubes. The 
glenoid surface of the pubes is a sigmoid, while that of the ischia is regularly convex. The articulation of the ilium 
has been exclusively with the former. 

Of the pleurapophysial portion of the two arches nothing appears to be preserved except two lateral symmetrical 
long bones. One was found imbedded in the mass carrying the pelvic arch, and they articulate well with the pubes; 
but the articular extremity is too short to articulate with ischia at the same time. Though they resemble the inferior 
view of the procoracoids, they represent the ilia of Plesiosaurus. The head is subdiscoid, rather flat, slightly pro- 
jecting excentrically with a ligamentous pit. The articular surface is very oblique to the axis of the shaft, and is 
separated from the surface by a marked angle all around. Nothing like a trochanteric ridge is apparent in this bone. 

Length in middle of curve. 

Diameter at head, 

' ' distally on curve, 
" " straight. 











Fig. 8. 

Fix. 9. 

Fig. 10. 

Pelvic Arch. 

The shaft is flattened cylindric ; much flattened nearest the proximal extremity. The latter is very oblique to 
the shaft and slightly convex near the proximal margin. 

The end of the muzzle preserved, includes also the symphysis and parts of the rami of the mandible. The parts 
have been crushed together, and the ends of the teeth broken off. The alveoli of the two jaws incline at a narrow 
angle to each other, hence the teeth which alternate, cross each other near the middles of the crowns. The parts 
preserved appear to belong to the premaxillary bone, though no suture can be found, and the bony walls are so thin 
as to render their obliteration a probability.- There is a keeled ridge along the middle line above, which is not 
continued to the margin of the bone. The form of the muzzle is narrow, the sides subparallel near the tip, which is 
elongate rounded. The mandibular symphysis, however, is not very elongate, as the rami are given off at three inches 
from the tip. The latter appear to have been quite slender from various small sections or pieces sent with the muzzle. 
The premaxillary border of 4 in. 7 lin. exhibits eight teeth, or their alveoli, of which the median two are close 
together, and not separated by any mandibulars. The sections of the teeth are round or oval, and their sizes are 
irregular probably on account of differing age, and degree of protrusion: the diameters at alveolar margin vary from 
6 lines to 3. Their form is slender conic, or with the root slender fusiform, and the pulp cavity is small and median. 



Fig. 12. 

sometimes cylindric, and somtimes nan-owed. The surface from a short distance ahove the alveolar margins to the 
tip, is marked with acute thread-like ridges, which are sometimes interrupted, and some- 
times furnished with short branchlets. They are more or less undulate, and do not unite, 
but simply cease as the tip of the tooth is approached. The latter is smooth without lateral 
cutting edges. The width of the mandible at the commencement of the rami is 3 in. .05 
lin. ; of the muzzle of the seventh tooth 3 in. 7.5 lin. ; at the third tooth 2 in. 4.2 lin. 

General Remarks. — The tail is a powerful swimming organ, more or less compressed in 
life, hence the specific name, which means flat-tailed. 

The danger of injury to which such an excessively elongate neck has been exposed, would 
render the recovery of a perfect specimen like the present, an unusual chance. The neural 
spines of the dorsal region are so elevated and closely placed as to allow of little or no vertical 
motion of the column downwards, while those of the cervical and caudal region being nar- 
rower, the elevation of the head is quite possible, and an upward flexure easy. 

The habit of this species, like that of its nearest known allies, was raptorial, as evinced 
by the numerous canine-like teeth, and the fish remains taken from beneath its vertebra?. 

The general form of this reptile, whether it was furnished with large posterior limbs or 
not, was that of a serpent with a relatively shorter, more robust and more posteriorly placed 
body than is characteristic of ti-ue serpents, and with two pairs of limbs or paddles. It pro- 
gressed by the strokes of its paddles, assisted by its powerful and oar-like tail. The body 
was steadied by the elevated keel of the median dorsal line, formed by the broad, high neural 
spines. The snake-like neck was raised high in the air, or depressed at the will of the animal, 
now arched swan-like preparatory to a plunge after a fish, now stretched in repose on the 
water or deflexed in exploring the depths below. 

Differences from other Sauropterygia. — The only genus with which it is necessary to com- 
pare this present one is Chnoliasaurus. The following may be noted as generic distinctions: The 
series of cervicals rapidly diminishes in Cimoliasaurus in absolute size and in relative length of the vertebra?, 
which are not compressed. In the present genus they maintain a similar length for a considerable distance, 
diminish in length very gradually and are much compressed. The diapophyses of the dorsal vertebra?, 
as they descend, in Cimoliasaurus, continue well developed until they attain the inferior planes of the 
centrum, and have there a downward direction. In Elasmosaurus they cease while yet on the middle of 
the centrum, and are replaced by pits throughout the remainder of the length. 
The neural canal is everywhere markedly larger in Cimoliasaurus. 

As the characters of lesser significance may be added, that in Cimoliasaurus magnus the dorsals 
with elevated diapophyses are considerably larger in the centra than those in which they are situated 
lower down. In E. platyurus these vertebra? are of relatively equal length. 

The cervical pleurapophyses in C. magnus are anteriorly considerably stouter and less flattened- the 
same applies to more anterior vertebra?, where they are flatter in both. 

In comparing this species with the Cimoliasaurus grandis, Leidy, from Arkansas, we observe first 
the generic character of the strong inferior diapophyses in the latter. That species marks itself also 
as a preeminently short-necked form, as these anterior dorsals are even shorter than in C. magnus, beinn- nearly twice 
as wide as long. The depth of the articular faces is also relatively greater than in the E. platyurus. 

History. — The determination of the extremities of this species was rendered difficult from the fact that Leidy in 
his descriptions of Cimoliasaurus, reverses the relations of the vertebra?, viewing the cervicals as caudals and lum- 
bars, and describing the caudals as belonging to another genus. Not suspecting this error, I arranged the skeleton of 
Elasmosaurus with the same relation of extremities, and the more wiflingly as the distal cervicals present an extraor- 
dinary attenuation, even for this type, and also as the discoverer assured me that the fragments of cranium were 
found at the extremity which is properly the caudal. Viewed in this light many details of the structure were the re- 

DO fl 




)0 fa 

/ ..,i,v \ 

) 00 




verse of those ordinarily observed among reptiles, whence I was induced to consider it as the type of a peculiar 
group of high rank. This new is, of course, abandoned on a correct interpretation of the extremities. Leidy 
detected the error in this arrangement, and the correction extends to Cimoliasauras as well. 


This species is indicated by two vertebra?. The first resembles both the twelfth from the first dorsal of the cervi- 
cal series of Cimoliasaurus magnus, or the fifth from behind, of the same of Elasmosaurus. Its large size, lateral 
longitudinal angle and small neural canal refer it with more probability to the latter genus. It appears to belong to 
a species possessing some of the peculiarities of the Cimoliasaurus magnus, having the quadrate form of the median 
cervicals of that animal, and lacking entirely the compression of the centrum and lateral concavity of the E. platyurus. 
The parapophyses are stronger and slightly more descending than in the fifth cervical of the latter, again resembling 
the more posterior vertebra of C. magnus Leidy. The bases of the parapophyses are more elongate than in the cor- 
responding vertebra of C. magnus; the process was directed downwards at an angle of 45°, from the plane of the in- 
ferior aspect. The inferior plane is slightly concave, with two venous foramina, each in a strong groove on each side 
of a narrow median rib. The lateral surface is nearly vertical and slightly concave to the strong longitudinal angle. 
Above the latter the face is oblique concave for a width equal to that below. The articular faces are transverse ovals 
and slightly concave; their margin not prominent, nor ribbed on the lateral faces. 

Length, 45 

"Width, 52 

Depth to canal, 36 

Width canal, 7.7 

Length basis of parapophysis, 25. 

If we estimate this vertebra by the position of the lateral ridge to be about the eighth anterior to the last rib- 
bearing, which I call cervicals in this genus, the transverse diameter of this vertebra in C. magnus is 
two-thirds that of a dorsal with diapophyses near the middle of the centrum. Should the proportions have been 
similar in this species, the diameter of that dorsal would measure 6j inches, indicative of the largest of American 
saurians. As, however, in the genus Elasmosaurus the disproportion between the sizes of the caudals and the dorsals 
is less than its ally, the latter have probably presented a diameter more like the same in E. platyurus. 

A second vertebra from near the same part of the column of a much larger individual was obtained by Dr. Samuel 
Lockwood, superintendent of schools of Monmouth County, N. J., from Win. Conovers' pit in the lower bed, near 
Marlboro, in that county. The diapophyses are directed downwards at an angle of 45°. The margins of the articular 
faces are not everted, while the inferior presents an open emargination medially. The two inferior foramina are very 
large. The measurements are as follows: 

Width of articular surface, 
Depth do. do., 

Length centrum, 

The name is not given under any supposition of restricted habitat, which may have been similar to that of the 
E. platyurus, but in view of the probability of its greater abundance where its remains have been found than 

Our knowledge of this species is unfortunately confined to the two vertebras above described. The first is 
from the lower cretaceous greensand bed, from near Swedesboro, Gloucester Comity, New Jersey. It was found in a 
tailor's shop used as a block to secure a door. 










Incertae sedis. 



Cretaceous Rept. N. Am., 29, 30, Tab. 

Cretaceous of Red River Settlement, Lat. 49 deg., Northern Minnesota. Described from a tooth. 

Owen in part. 

In this suborder we have a singularly generalized group, combining characters of 
lizards, crocodiles and Sauropterygians. The neural arch of the vertebrae united by suture 
and the slightly biconcave centrum, resemble the last two, so also the abdominal ribs. 
The limbs are rather crocodilian, the position of the nares, Plesiosaurian. The clavicle is 
lacertian, while the three vertebrae of the sacrum and the femur are between these and 
the Dinosauria. 

The most important characters distinguishing these animals from the Sanropterygia 
are the presence of an elongate sacrum and the more ambulatory form of limbs. 

Our knowledge of the order is almost confined to Belodon Meyer, and is derived from 
that author's descriptions of those large and remarkable reptiles derived from the Keuper 
of Wiirtemburg, the Belodon kapfii Meyer, B. plieningeri Miinst., and B. planirostris 

The American species of the order are known only from the valuable collections made 
by Wheatley at Phcenixville, Pa., and by Emmons at Deep River, in Chatham county, 
in North Carolina. The former are in my hands for examination and description, and 
will be the subject of an appendix to this work. 

BELODON, Meyer. 

Although this genus does not present the swimming extremities of Plesiosaurus and 
Nothosaurus, its structure in this respect is not much more different from them, than 
that of the marine turtles is from the terrestial families of the same order. The 
structure of the sphenoidal region, the peculiar position of the external nostrils, almost 
above the orbits, with the rhizodont dentition, are points in which they agree. The 
position of the exterior nares cannot be regarded as an ordinal character, since we see 
what remarkable differences of position it exhibits in the existing family Varanida;. 
There is is every probability that these animals were aquatic. The posterior position of 
the nostrils, like that in many other marine animals, enabled them to plunge the long 
muzzle beneath the surface of the water or mud without interfering with respiration. 

The dentition of the posterior parts of the mouth has been shown by Von Meyer to 
be quite different from that of the anterior regions; the latter are prehensile, that is 
elongate conic, the former cutting, i. e., flattened, broader and with trenchant edges. 


On teeth of the latter kind Emmons established his Palceosaurus carolinensis and P. 
sulcatus; and Leidy, Compsosaurus priscus and Eurydorus serridens. On teeth of the for- 
mer kind Emmons based his Clepsysaurus pennsylvanicus in part; bis Rhytidodon caro- 
linensis and R. sulcatus; Leidy's Omosaurus perplexus and Lea's Centemodon sulcatus had 
a similar origin. The names based on the lenticular teeth accompany, as prior to, or 
synonymes of, the latter series. There is much difficulty in collating them, but 1 may 
follow Emmons at present, in seeing in the two styles of smooth and fluted teeth, those 
representing different species. 

In this way I have attached to the fluted toothed Rhytidodon carolinensis, Emmons, 
the Palceeosaurus sulcatus of the same author. Emmons does not offer any grounds of 
separation for his R. sulcatus, nor Lea his Centemodon sulcatus; neither can I find aught 
in Leidy's Omosaurus perplexus by which it can be separated. Leidy represents it to be 
an " Enaliosaurian," while Emmons says (North American Geology, 67-79-82), that it is 
the same as his Clepsysaurus and Rhytidodon, citing Leidy as authority for this close ap- 
proximation. If this be the case, the form is a shore-loving Belodont, and not nearly 
related to the marine reptiles included under the old name of Enaliosauria. 

To the smooth toothed type belong posterior teeth named by Emmons, Palceosaurus 
carolinensis, and by Leidy, Compsosaurus priscus and Eurydorus serridens, and anterior 
teeth referred, erroneously in part, as I believe, to Clepsysaurus pennsylvanicus, Lea. The 
first mentioned name cannot be used, as it has been already applied to a member of this 
genus. The third was based on a specimen from a very remote locality, and its proper 
application remains uncertain. The second specific name may be employed in the uncer- 
tainty, though its describer included both fluted and smooth teeth in the same species. 

Specimens in the Academy Mus., from Montgomery Co., N. Ca., consist of vertebra?, 
tarsal bones, etc., and parts of cranium with dermal bones of this species. A tooth in 
place in the extremity of the ramus of the mandible, is as smooth as those from more pos- 
terior positions in the jaw, figured by Emmons, N. Am. Geol., p. 69, fig. 42, which in 
some measure supports Emmons' hypothesis of the uniformity of the characters of the sur- 
face sculpture. The cranial fragments indicate a Belodont, and the vertebra? are different 
from those of Clepsysaurus. 

The vertebra?, (No. 5) from the coal of Chatham Co., N. Ca., were accompanied by 
teeth of the fluted character, though they were not on the same block. As the former 
indicate a species distinct from that from Montgomery Co., 1 have regarded them as pro- 
bably pertaining to Emmons' Rhytidodon carolinensis. 

The remains, (No. 6) from Phcenixville, include vertebra?, bones of the pelvic arch and 
posterior limb, with dermal bones, but no teeth. They indicate an animal distinct from 
either of the preceding. 



Emmons describes a species Clepsysaurus leaii, from the coal strata of Dan River, 
from near Leakesville, N. Ca., which appears to be distinct from the Bhytidodon earth 
linensis. It is represented by a cast of a block of sandstone containing 14 vertebrae, etc., 
which indicate a species different from any of those above mentioned. 

Finally, although the Eurydorus serridens, Leidy, from its locality (Phcenixville, 
Pennsylvania), may indicate a fifth species, there is nothing in the type specimen, nor in 
the description, to determinine any reference. It cannot safely be regarded as the same 
as the Belodon here described, from the same locality, since the strata in which the two 
occur, are separated by a vertical thickness of 187 feet of rock. 

Having satisfied myself of the existence of four distinct species of Belodonts in our 
Triassic beds, their generic relations come next in order for consideration. 

In his Manual of Geology, Prof. Emmons figures the cranium of a Reptile (fig. 157, 
page 179), which bears a near resemblance to that of the Belodon plieningeri, Meyer. 
The cast of this cranium in the Museum of the Academy Nat. Sci., confirms the reference 
to this genus, and presents no characters by which it can be distinguished from it. The 
specimens (No. 4) consist in part of the short frontal bones with part of the orbits and 
cranial cavity, and a portion of the ramus of the mandible, of a saurian near the genus 
Belodon, perhaps the same. The ilium figured by Emmons (N. Amer. Geology, p. 77, 
fig. 47,) and the femur, (fig. 48), with portions of mandibular ramus (fig. 42), obviously 
indicate Belodonts. 

Of the Phcenixville saurian, portions of the ilium and ischium are preserved, which 
indicate that the auimal is neither a Dinosaurian nor a Dicynodont, nor yet a Crocodile. 
The portion of ilium answers to that of Belodon, as figured by Meyer and Emmons. 

The Dan River species is referred to the same group without entire certainty. The 
only teeth occurring in the same strata are, according to Emmons, identical with those of 
the smooth toothed Belodont from Deep River. The cervical vertebrae are quite similar 
to those of the Deep River species. 

I can as yet find no generic characters by which to distinguish these species from the 
Belodon of Meyer, neither in the cranial, dental, pelvic nor extremital regions. Meyer 
describes and figures numerous teeth, both smooth and sulcate, without distinguishing the 
two forms specifically, though it is certain that three species of the genus came under his 
observation. He figures ilia of two species, one of which cannot be distinguished genet- 
ically from that figured by Emmons (1. c. fig. 47). 

This genus was referred by Owen to the Thecodontia, along with some other little 
known genera. Some of the latter, especially Bathygnathus and Clepsysaurus, are in 
our opinion Dinosaurian, while others, as Belodon, represent a family of the present order. 



Proceed. Ac. Nat. Sci., 1866, 249. Rutiodon (Rhylidodon) earolinensis Emmons' N. Ainer. Geology, p. 82. 
Geol. Suit. North Carolina. Palaeosaurus sulcatus, Emmons loc. cit. (posterior maxillary teeth), Fig. Emmons 
Manual of Geology, p. 179. Ccntemodon sulcatus, Lea. Proceed Ac. Nat. Sci., Phila, 1856, 78. Cope, 1808, 221. 
? Omosaurus perplexus, Leidy, Proceed. Ac. N. Sci., Phil., 1856, 256. 

This reptile I find on examination of the type specimen to belong here. Teeth of the same are in Wheatley's 
collection at Phcenixville. I do not consider that any ground of specific distinction between this animal and the C. 
sulcatus has been pointed out, but leave the discussion of the relations of these Triassic forms for a future essay. 

Lea has called my attention to the fact that through some error in reading the scale, the measurements of tin- 
type tooth published ai-e double the correct ones. The specimen consist of the distal half of a slightly curved conic 
tooth, and does not display any pulp cavity; the allusion to this in the original description having reference to frac- 
ture. The tooth cannot be called sulcate, but is rather weakly ridged or fluted. The original description may 
therefore be amended to read thus: 

Tooth slightly curved, with low trenchant edges, rounded on the exposed face, openly fluted on the lower 
(median) portion near the fracture, covered with very minute distinct striae from the point to the base, which stria; 
cross to the flutings in oblique lines. Length, eight-twentieths of an inch ; greatest breadth, two-twentieths ; pulp 
cavity minute or none. 

The enamel of the teeth of B. earolinensis is rarely preserved; when this is the case its striae, fluting, etc., are 
as ascribed in C. sulcatus. 

Coal Measures of the Keuper Trias. Chatham Co., N. Carolina. 


Palaosaurus earolinensis, Emmons, Geological Survey N. Ca., 1856, p. 80. N. Amer. Geology, 1857, 86, figs. 57-8 
60. nee Rhytidodon earolinensis supra. ? Compsosaurus priscus, Leidy, Proc. Acad. Nat. Sci., Phila., 1856, 165. 
Clepsysaurus pennsylvanieus, "Lea," Emmons in parte, Geol. Survey N. Carolina, 1856; North Amer. Geology, 1857, 
pp. 67-71-3; figs. 37 to 50 nee Leaii. 

Represented by numerous specimens from the Triassic of Chatham and Montgomery counties, N. Carolina. Teeth 
not fluted; caudal vertebras with articular faces broad as long, and centrum little compressed. Size medium. 


Clepsisaurus leaii, Emmons, Geol. Survey N. Ca., 1856; N. Amer. Geology, 1857. p. 79, fig. 51, PI. 8, figs. 1— t. 

Emmons states that this species is smaller than the last, and that the centrum is longer than broad. Cervical 
vertebrae short, compressed, extremities strongly concave. The Trias of Dan River, N. Carolina. 

Spec. nov. 

Represented by wholes or parts of fourteen vertebra?; a left femur and fibula; a phalange; imperfect ilium and 
ischium attached; with numerous ribs and dermal bones, from several blocks of bituminous shale from the bone bed in 
the tunnel at Phcenixville, Penna. 

The fragments indicate the largest species of the genus, one of the vertebras with spine, measuring eight inches 
in total elevation. The centra of the dorsals are wider at the articular faces thau long; in the other two species the 
length is greater than or equal to the width. The caudal vertebrae are much compressed, not subeylindric as in B. 
priscus. The femur restored measures thirteen inches in length. Ischium sending a process forwards bounding the 
acetabulum below in part, largely excavated by the obturator foramen, which is very externally situated. 

The bones were enclosed in five slabs of black, bituminous argillaceous rock of the Phcenixville section, and they 
were taken out from the same immediate proximity by the workmen engaged in the work in the tunnel. One slab 
contained three dorsal and two caudal vertebras with chevron bone. The second, one and part of another dorsal ver- 


tebrae and the head of the femur; the third a nearly perfect vertebra and diapophysis of another, with dermal bones; 
the fourth the greater part of the femur, with fibula and dermal bones; fifth, ribs and dermal bones, with pelvis. 

Seven vertebra present centra, and are more or less nearly perfect. There are probably no cervicitis, but there are 
three forms of diapophyses which indicate different positions in the vertebral column. 

That which I suppose to represent the most anterior, has a short, wide diapophysis with tubercular articular sur- 
face, and a short knob with capitular articulation at the base of the anterior aspect of the neurapophysis, with its su- 
perior margin on the plane of the diapophysis. In the next, the diapophysis is short, wide, and closely connected at 
the base with a capitular articular tubercle, for the rib, the extremity of the diapophysis furnishing the tubercular 
surface. In the first of these the diapophysis is as long as the elevation of the anterior zygapophysis above the cen- 
trum, and the capitular knob measures the middle of the latter space with its superior margin, being in the plane of 
the diapophysis. In three others the elevated position of the capitular articulation is visible. The second form of 
diapophysis is seen in a nearly perfect vertebra in immediate connection with that first described above, but probably 
in abnormal relation. The process is narrower, but flat, and without capitular process at base, nor is there any cap- 
tular articulation on the centrum. Its position is much lower than in those just described, being opposite to the 
middle of the centrum. Its extremities are imperfect, probably broken off. I suspect that their condition is indicated 
by an isolated diapophysis, which is accompanied by tubercular articular face at a distance of 18 lines from its extrem- 
ity, and probably at some distance from its base, which is, however, lost. The third type of diapophysis is seen in two 
examples; one, in normal relation to its centrum, etc. This is quite slender and elongate, compressed at base, and 
cylindric throughout most of the length. On the posterior face of the extremity is a slightly concave articular face; 
the extremity proper appears also to have borne the tubercular face. That these are the combined tubercular and ar- 
ticular facets is rendered altogether probable by their wider separation on the second example of this form. This is 
an isolated diapophysis, of slender cylindric form, which, at a distance of an inch from the extremity dilates into a 
right-angled flat process, whose distal side bears a narrow capitular articular face. The extremity is subcylindric, 
bearing the tubercular facet. 

This arrangement of the vertebra? is confirmed by the arrangement seen in other species, where vertebras similar 
to those first described are evidently dorsal. It is probable from the above, that the capitular articulation rises from 
the centrum very soon in this type, as in the Crocodilia, perhaps very few dorsals retaining it on that portion; and 
differing from the Dinosaurian type, where this facet is on the margins of the centra and not elevated on a pedicel. 
This form differs from the Crocodiles in the narrowing and final cylindric form, as well as descent on the centrum of 
those diapophyses on which the two facets approach and unite. 

One objection to the position assigned to the last form of vertebra, is the fact that the only one with perfect cen- 
trum presents an oblique truncation on the posterior margin on each side, which looks much like a capitular articular 
face. There is a precisely similar vertebra in the Museum of the Acad. Natl. Sciences, from Chatham Co., N. Ca., 
which is ascribed to the B. caroliuensis. Their surface is concave in this specimen, but seems too large for the head 
of a rib. In both, the vertical diameter is one-half the transverse width of the articular face of the centrum. I can- 
not assign the place or use of this facet with certainty, but the following light is thrown upon the point by another 
specimen in the Museum Academy, also from Chatham Co., N. Ca., presented by Prof. Emmons. 

It consists of five consecutive vertebrae on a block of coal slate, of which the anterior two present the capitular 
tubercle elevated to the base of the short flat diapophysis, without being confluent with it in the first, but closely 
united to, and of equal length with the shortened second. On the third, the rib-diapophysis becomes abruptly very 
much wider, and occupies a position a little lower down on the centrum. The diapophysis is preserved on one side of 
the block. It is flat, a little narrowed beyond the middle, then dilated, and with an open emargination opening pos- 
teriorly and outwards, at the distal extremity. 'With the extremity it bears a narrow articular surface. These I sus- 
pect to represent capitular and tubercular articulations. The fourth and fifth vertebra; bear each, a greatly dilated 
and thickened diapophysis, which I have little doubt represent the sacral supports of the ilium. Their expanded 
bases are somewhat lower in position than the diapophyses of the vertebra in advance, and they occupy a broad arti- 
cular face of their proper vertebra, and a distinct facet of that preceding, leaving an articular face on its posterior 
margin. I suppose the peculiar vertebra; already alluded to iu the B. lepturus and specimen from North Carolini, 
are, therefore, the last lumbars. 


From the above, four points may be derived: 1. That the ribs are continued to the sacrum in this type, a char- 
acter not before pointed out among its representatives in this country or Europe, and one in which it differs from the 
Crocodilia from the Cretaceous to the present period inclusive. 2. That the sacral diapophyses articulate with two 
vertebras instead of one, a point similarly exceptional with the last point. 3d. That in both these points this type 
approaches the Dicynodontia and Dinosauria, as it does in some others. 4th. That the B. lepturus belongs to a dif- 
ferent species' from that from N. Carolina, last described, in having at least three diapophyses witli double articulation 
near the extremity instead of one, and to a different genus from the same, because several of these are cylindric in the 
former, and broadly flattened in the latter. 

"Which genus is distinct from Belodou is difficult to ascertain. If we suppose B. carolinensis to represent it, as it 
certainly does in cranial characters and other respects, the North Carolina specimen will represent another genu-, 
since a sacral vertebra of B. carolinensis presents all the characters of that of B. lepturus. 

The centra of the vertebras are very much compressed, and the articular faces flared out at the margins. The 
faces are wide vertical ovals and distinctly concave. The posterior face of the supposed last dorsal is flattened, and 
presents two slightly swollen triangular planes, each from the facet of the margin. 

The neural spines of the anterior vertebras are shorter and wider, of the posterior more elevated and narrower. 
The rib supporting the anterior zygapophysis is very prominent in all, as is that defining the margin of the neural 
arch. They include a short vertical concavity between them, giving the vertebrae a marked character. 

The eaudals are very much compressed, more so than in B. ?priscus, though since they are median in the series. 
and those of the latter are proximal, there would probably be a greater resemblance between the homologous ones. 
The articular extremities are vertically oval, and but little flared at the margins. The neural arch with its apophyses 
is compressed. The diapophyses project just below the base of the arch, and are depressed and stout. 

Measurements. IT. 

Vertebra 1st type, 0.18 

Do. height neural spine from canal, 0.10 

Do. length diapophysis, 0.026 

Do. " centrum, 0.05 

Do. diameter centrum .middle, O.021 

Do. " " articular face, 0.055 

Do. " " vertical, articular face, O.059 

Total elevation type 2d, 0.1951 

Do. neural spine from canal, 0.122 

Do. width do., 0.04 

Do. length centrum, 0.05 

Do. diameter (transverse) centrum middle, 0.023 

Do. " " " artic. face, 0.054 

Do. " vertical " " 0.06 

Do. elevation type 3d, 0.186 

Do. neural spine from canal, 0.11 

Do. length centrum, 0.049 

Do. diam. (transverse) centrum at middle, 0.032 

Do. " " " artic. face, 0.061 

Do. " vertical " " 0.062 

Do. expanse anterior zygapophyses, 0.07 

Do. diameter neural canal, 0.02 

Length diapophysis, 0.082 
The neural canal in the vertebra first described, is narrower and more elevated than in the last dorsal. 
A chevron bone has nearly cylindric limbs and short common junction of the same. Their proximal extremities 
are considerably expanded, but not so as to meet on the median line. They are very oblique backwards and inwards. 
Distal extremity strongly striate. 


M. M. 

Length, .075 Inner, .005 

Proximal expanse, outer measurement, .052 
The portion of the pelvis preserved consists of the proximal halves of left ilium and ischium, the anterior portion 
of the latter being broken away. This fragment is not Dinosaurian; the longitudinal expansion forbids the reference 
of the ilium as the ischiopubis of a Dicynodont, and the ischium is too different to be regarded as the scapula of a 
Belodont. It presents a broad shallow concavity as acetabulum, which on the inner face is grooved and ridged at the 
inferior margin, as though united to the ischium by suture. This is well shown in Emmons' figures of the same bone 
of another species, in North Amer. Geology, PL VI. The upper plane of this element is abruptly curved backwards 
and then broken away. The supposed ischium presents a marked acetabular articular face at its posterior connection 
with the ilium. Its posterior margin is much thickened, and becomes decurved towards the symphysis, which is lost. 
It sends a limb anteriorly along the line of union with the ilium, and apparently terminates in a narrow obtuse ex- 
tremity with rugose margins. Its supposed obtruator margin is thickened along this process; the main body of the 
bone is flattened at a strong angle with the posterior margin, and turned away anteriorly like the ilium of a Dicyno- 
dont, and includes an incomplete oval foramen with the acetabular process. The two pelvic elements are crushed 

nearly into one plane. 

M. 31. 

Length of fragment, 0.167 Width ischium at foramen, .055 

" ilium to posterior process, .0715 Thickness " distally, .021 

" iliac suture of ischium, .092 

The mode of attachment of the pubis is not indicated in this specimen, but it was evidently quite different from 
that in the Crocodilia. 

The femur is that of the left side; it is perfect, except that the portion usually supporting the third trochanter is 
broken out; say two inches. The head is Crocodilian, i. e., without neck and compressed in one plane. Its extrem- 
ity is slightly convex inwards, the inner extremity thickened, convex and decurved; the extero-posterior thinned and 
curved backwards slightly. The margin continued from the latter is therefore thinned, though obtuse edged, and 
encloses a wide shallow groove with the inner, thickened margin. There are no distinct trochanters. The shaft is 
quite slender, obliquely spherical triangular in section, with an inner ridge in front, and outer behind. The medul- 
lary cavity is very small. At the distal third the shaft is flattened antero-posteriorly. The trochlear groove is wide 
and shallow, and the condyles project less posteriorly than is usual; they have, however, been under considerable 
pressure. The inner is wider and shallower, the outer narrower and deeper. Their extremital faces are separated by 
an open notch. 

The fibula is a long slender bone, having a slight sigmoid flexure, and ridges twisted round the flattened shaft. 
The extremities are more flattened, both in the same plane; the proximal is broken away; the distal is obtuse, one end 
terminating in a point; the surface rugose. Its form is Lacertilian. 

M. M. 

Length femur, restored, 0.34 Diameter condyles, inner, fore and aft, 0.045 

Diameter head, anteroposterior, 0.09 Length fibula, broken, 0.24 

" " transverse (greatest), 0.044 Diameter perfect extremity, 0.035 

shaft at middle, 0.045 " imperfect " 0.042 

" condyles, transverse, 0.083 " shaft, 0.025 

What is doubtfully referred as a distal phalange, resembles that ascribed to a species of the genus by Meyer, but 
as I cannot find lateral grooves, and the proximal articulations are concealed by matrix, it may not be such. One 
lateral margin is obtuse, the other acute; body thinned out to tip, flat in cross section below, concave in longitudinal, 

as wide distally as proximally. 

M. M. 

Length, .035 Depth proximally, .0165 

Width distally, .017 

Surface striate-rugose; lines of the upper surface converging toward a median point from the base. 
Several more or less broken, and one complete rib are preserved. The two heads are distinct. The perfect rib 


is perhaps a posterior dorsal. It is but slightly curved, has a vertically broad oval section proximally, and a depi eased 
trigonal one distally; there is little trace of a medullary cavity. 

M. M. 

Length, 0.23 Vertical diameter at distal third, 0.014 

Do. from head to tubercle, 0.03 Transverse do., 0.153. 

I find no abdominal ribs, such as are abundant in the North Carolina specimen described on a pieceding page. 

This species has been distinguished from B. priscus by the form of its caudal vertebra. The measurements given 
by Emmons and Leidy, of the other species, differ in the greater elongation of the vertebral centra. The length of 
the latter is in each case greater than the width of the articular face, instead of less. They are also smaller in all 
their dimensions. We shall not go very far wrong in estimating the length of this species on the basis of the gavial 
of the Ganges, as furnished by.Cuvier. This would give to the Belodon lepturus a length of about ten feet, and a 
habit stouter than that of the Crocodiles of the present day. 

This species was discovered by Chas. M. Wheatley, proprietor of the lead and zinc mines at Phoenixville, Penna. 
He obtained the remains from the "Bone bed" of the Trias, where exposed by the Phoenixville Tunnel of the Read- 
ing Railroad. This stratum is, according to Wheatley, ft. 6 in. from the top of the series; 52 ft. 6 in. lower down 
is a stratum rich in plants and Saurian remains, and 95 ft. deeper occur bituminous shales with caprolites and bones. 


The constitution of the cranium in this order is very characteristic and peculiar. The 
basal cranial bones are forced backwards, so that they occupy a more or less vertical posi- 
tion, and the sphenoid is almost concealed in many. The quadratum is immoveably 
embraced by the exoccipital, prootic and opisthotic. The pubes do not enter into the 
walls of the acetabulum as in Mammalia and Reptilia, but originate from the inferior 
pelvic arch. They form no common suture, but extend sub-longitudinally, thus differing 
from pubes generally. The latter relation of true pubes occurs among Reptiles only in 
Chelys, Pelomedusa galeata, and Sternothaerus, among the Chelonia, and in Pterosauria. 
An anterior process from the ischium occupies the usual position of the origin of the 
pubis, as a support for the latter. 

There are at least two well marked types in the class, defined as follows: 
Vertebrae procoelian, i. e. with anterior cup and posterior ball; the sphenoid bone 
little visible on the base of cranium. 


Vertebras concave or nearly plane at both extremities ; sphenoid bone with larger and 
more horizontal exposure on base of cranium. 


The only genus of Amphicceli known in this country is Hyposaiirus ; the Procoelian 
genera are the following: 

A The teeth composed of several enclosed cones of dentine. 

« The cervical vertebras with very rudimental or split hypapophyses. 

A large fossa or foramen issuing between the prefrontal and lachrymal bones of the 
face ; muzzle long, slender, teeth equal. 



No facial foramen ; muzzle long slender. 


aa The cervical vertebra? with long simple zygapophyses. 
Muzzle long narrow, with long symphysis ; teeth very unequal. 


Muzzle broad short, symphysis short. 


AA Teeth crowns a single dentinal cone with enamel sheath. 
Cervical hypapophyses rudimental ; muzzle broad. 


Cervical hypapophyses elongate, simple. 


Species of this order have been abundant in North America from the beginning of the 
Cretaceous period to the end of the Miocene. At present they are confined to its extreme 
southern regions. 

The Cretaceous period was more prolific in them than any later one, for then the 
Reptilian type in all its representatives reached its fullest development in the numbers, 
variety and size of its members. Then our sea coasts, estuaries, and fresh waters 
swarmed with them, an indication of the prolific lesser life on which they preyed or 
otherwise vented their powers of destruction. 

Proceedings Academy Natural Sciences, 1867, p. 143. 

This genus was characterized from a few teeth from the Miocene of Maryland. 
Since then additional material has enabled me to construct its characters more fully. 

Muzzle elongate, slender, as in Gavialis, the symphysis of the mandible elongate ; den- 
tal series interrupted by larger canine-like teeth. Dentine of the crown arranged in 
concentric cones. Enamel thin, with a delicate anterior and posterior cutting ridge near 
the tip of the crown. Cervical hypapophyses elongate, simple. 

The concentric structure of the dentine in this genus is quite the same as in Thora- 
cosaurus. I do not discover in it sections of the teeth of Gavialis, Mecistops and Croco- 
dilus. The cones readily separate and fall out in the fossil specimens. Their existence 
would indicate a periodical cessation of activity in the secretory vessels on the wall of the 
pulp cavity of the teeth, with intervening increase of deposit of dentine. In a shed tooth 
of this genus four such cones may be counted.f 

*Probably the thin crown in this genus is composed of several attenuated cones. 

\k. supposed affinity of this genus to Mosasaurus, which I inserted in the original description, at the suggestion of 
a friend, I do not now recognize. 


This genus presents the same peculiarity of dentition as the Plerodon Meyei {Dvplocy- 
nodus Pomel) of the European Miocenes. The P. plenidcns, and P. ratelii are Loth of 
the Crocodilian type of cranium, the rami of the mandible with curved extremity and 
short symphysis, while Thecachampsa is a gavial, Avith very long symphysis and slender 
muzzle. I have seen but one cervical vertebra from American tertiaries, and that is of the 
type of Thoracosaurus ; hence this character cannot be certainly ascribed to Thecachampsa. 

Three species appear to exist in our Miocene beds. The T. sicaria indicates in its 
slender mandible one character of the genus ; it shows the surface to have been ridged 
and pitted as in other Crocodilia. The T. antiqua Leidy indicates in its dorsal vertebra, 
a smaller hypapophysis than in the known species of Crocodilus. T. sericodon Cope is 
only known from its teeth. The teeth of the three species may be thus distinguished. It 
must be mentioned that I have but one tooth of T. sicaria, three of T. antiqua and six of 
T. sericodon. In the first the tooth has a lenticular section a short distance below the tip, 
owing to the great development of the lateral cutting ridges, and the compression of the 
crown at their bases. In the other two, these ridges are much less developed; in T. 
antiquus they exist only towards the tip on the inner or concave face of the tooth, while 
in T. sericodon they extend more than half the length of the crown towards the base, on 
the inner side. 


Proceed. Ac. Nat. Sei., Phila., 1869, 8. 

This species is represented by a lumbar vertebra, an imperfect crown of a tooth, and a portion of the under jaw. 
They were submitted to me by Philip T. Tyson, State Geologist of Maryland, who procured them from near the 
mouth of the Patuxent River, along with the remains of Eschrichtius, Physeter, and other Cetacea. 

The portion of mandible indicates an animal of a size considerably exceeding both the Gavial of India and the 
Thoracasaurus of the Cretaceous of this country. It contains all or parts of alveolae of six teeth. Opposite the 
fourth alveolus from the front, the margin diverges slightly from the median line, indicating the position of the 
distal extremity of the splenial bone. The slight degree of this obliquity indicates an extensive contact of these 
elements, and not a symphysis formed merely by union of the dentary elements as in Mecistops and Crocodilus. As 
no curvature appears at the anterior extremity of the fragment, and the alveolae are similar to those succeeding, it 
has evidently not been broken from the anterior portion of the symphysis. The nutritious canal of the ramus is thus 
nowhere exposed, but is enclosed in the long symphysis. 

The upper face of the ramus is convex, most so anteriorly. Its lateral and inferior face is more convex than in 
other Gavials which I have noticed, especially posteriorly. Its surface is coarsely sulcate, and with numerous small 
foramina. A larger space than elsewhere is seen between the two median alveola?, which is occupied by a deep con- 
cavity for the reception of a large tooth of the maxillary series. This indicates an irregularity in the size of the 
teeth of that series, as in the Crocodiles, and not an equality as in other Gavials. On placing the fragment in position 
the teeth are seen to have diverged at an angle of 45°. 

The specimen had laid sufficiently long in the Miocene ocean bottom to have been fixed upon by barnacles and 
oysters, as a place of abode. That it had not remained unburied very long is evident from the small size which these 
parasites had attained ; and that it was buried in Miocene deposits and not worn by a more modern sea. is testified 
to by the Miocene shells (Turritella, etc.), whose fragments were removed from its cavities with the sandy clay of its 
place of burial. The teeth have been broken off in this rough contact with the elements, but I procured a large and 
characteristic portion of the crown of a successional tooth whose apex had attained to the level of the edge of the 


alveolus, and whose development had occasioned the absorption of half the fang of the functional tooth. On the basis 
of this tooth I am enabled to determine the distinctness of this crocodile from the T. antiqua. The crown, instead of 
being like that species, a cone with a circular section, with a narrow cutting longitudinal ridge rising abruptly from 
the surface on each side, in this tooth has a lenticular section, with the cutting ridges on the acute opposite angles. 
The external face is strongly convex, though not so much so as in T. antiqua. The edges are crenate, but not so as 
to produce a serration of the margin. Enamel finely obsoletely striate. 

The vertebra preserved is a posterior lumbar. The entire coossification of the neurapophysis indicates that the 
animal is adult ; their upper portions are lost. The diapophyses have had an oblique basis, rising anteriorly, their 
middle being opposite the plane of the neural canal, the whole length standing on the anterior two-fifths of the length 
of the centrum. The cup is subcircular, wider transversely ; the centrum is depressed ; below broad, with a median 
longitudinal concavity ; sides vertical. As compared with the dorsal vertebra: of T. antiqua, the latter are much 
more compressed in the centrum ; and although the posterior lumbars are. always more depressed than the dorsals, 
yet the present seems too much so to have pertained to the same species. It differs from those of T. antiqua also, 
in that the floor of the neural canal is entirely plane and smooth ; in the latter it is deeply grooved, in consequence of 
the non-coalescence of the expanded bases of the neurapophyses. 

Length fragment of mandible, 
Diameter of alveolus, 
Axial width from margin alveolus to symphysis above, 

do. do. do. do. below, 

Greatest width to median line (behind), 
Long diameter crown, at middle of length, 
Width muzzle, 
Estimated length cranium, 

do. total length, 33 

Length lumbar vertebra (centrum), 
Width cup, 
Height cup, 

The above estimate of length is based on the proportions of the Gavialis gangeticus as given by Cuvier. 


Crocodilus aniiquus, Leidy. L. c. 1851, 307. Journ. Ac. N. Sci., II., 135. Tab. ? ' Thecacliampsa contusor, Cope. 
Proc. A. N. Sci., 1867, 143. 

This species continues as-yet to be represented only by the specimens on which it was based, viz., two teeth, two 
vertebra;, an ungueal phalange, and a rib. These indicate a large species ; the vertebra} are even larger than that of 
the last, and the teeth will not enter its alveolae. It is probably the largest of the known Crocodiles of this country. 
Fig. 16. I have noticed only two dentinal cones in the two teeth we possess. 

The accompanying outlines are those of sections of the teeth of the present species, 
and the T. sicaria C. Fig. A represesents the former and fig. B the latter. 

The peculiar form of the tooth on which T. contusor was based, is due I find to attrition 
and partial destruction of the enamel. 
B A " Eocene " of Eastern Virginia from the banks of the Potomac. 

Proceed. Acad. Nat. Sci., Philad., 1867, p. 143. 

This species was established on fragments of three teeth from the Miocene of Maryland. Four additional and 
much more perfect teeth, with fragments of jaws, from New Jersey, presented by my friend, Dr. H. C. Wood, Jr., 
elucidate the characters of both species aud genus. 

























The most perfect tooth is slender and curved, and bears much resemblance to those "f Holops obscurus. 
The section of both root and crown circular, the latter regularly acuminate, and furnished with delicate cutting 
ridges. Terminal half smooth, basal half with a silky striation. Fang as well as crown, strongly curved. Cutting 

ridge descending as far on the posterior, as the anterior aspect of the crown. In a fractured New Jersey tooth, I 

count three dentinal cones. In one from Maryland, four. The inner cone is weakly fluted in both, but it scarcely 

affects the form of the enamel. 

The typical tooth of this species, as compared with the T. antiqua, is more slender and curved. In a length of 

crown and fang slightly exceeding the largest of the latter, the diameters are all about one-half the same. T 

from other portions of the jaw are but litle stouter. 

In. Lin. 

Length of tooth from New Jersey, (on curve, ) 3 8. 

Diameter at base crown, 6.6 

Length of Maryland specimen 16.5 lines. Base of crown, 9 lines. 
Miocene of New Jersey and Maryland. 


Sillim. Amer. Journ. Sci.Arts, 1869, p. 391. 

The enamel of the crowns of the teeth, is in this species quite rugose. The cutting edges are short, and promi- 
nent ; the' general form cylindric and but little curved. 

Miocene of Squankum, Monmouth Co., N. J. Mus. 0. C. Marsh. 


Crocodilus fastu/iatus, Leidy. Proc. A. N. S., Phil., 1851, 327. 
From Eocene of Eastern Virginia. 


The characters of this genus have never been pointed out to the knowledge of the 
writer. In the general form of the under jaw and teeth it does not seem to differ from 
Alligator. One character which separates it from that genus appears to be similar to 
that which distinguishes Thoracosaurus from Gavialis, i. e., the absence of long simple 
hypapophyses on the cervical vertebra?, and their substitution by low transverse or divided 
elevations. It also appears that the great external foramen which separates the angular, 
dentary and articular bones was closed up. 


Crocodilus harlani, Meyer Palaeologica, 1832, 108. Crocodilus macrorhynchus, Harlan. Jour. Ac. N. Sci., Phil.. 
1824, 15 (name pre-occupied). Bottosaurus harlani, Agassiz. Leidy, Cretaceous Rept. N. Am., 12-14, Tab. 

The teeth of this species are similar to those of Alligator in the short obtuse crowns. The pulp cavity is remark- 
ably large and extends into the crown, leaving the dentine and enamel at the apex little thicker than the sides. 

Besides the remains described by Leidy, portions of a smaller, perhaps younger, individual have been presented to 
the Academy of Natural Sciences by Dr. Ashhurst, from near Birmingham, N. J. They consist of various fragments 
of cranium with dermal plates. A tooth is compressed, but has a short conic acute crown, such as has not before 
been seen in this species. 

The interorbital region is strongly pitted medially, and exhibits on each side a deep, short groove. There are no 
marked crests. 



The dermal plates are about the size of Holops obseurus, but have smaller pits, wider intervals, and one margin 
without pits, but smooth and thinned out. 

"Width ramus where tooth series turns from inner to outer margin, 14.5 

" interorbital space, 14. 

" articular facet of mandible, 19. 

Length dermal bone, 25. 

It is difficult to refer vertebra to this species with certainty, as they resemble so closely those of Holops. The 
species is less abundant than those of the latter, and being found with them the vertebra?, are easily confused. It is 
not impossible, for instance, that those referred to H. tenebrosus belong to this animal, as teeth of the latter were 
found near the same time and place. There have, however, come under my observation some vertebrae different from 
those of any of the Holopes, which correspond in size and rarity with the present crocodile. A description is 
therefore appended. 

First — These are a fourth cervical vertebra, and some long bones, which were presented together to the Burlinir- 
ton County, N. J., Lyceum, and were procured at Gaskill's excavations near Birmingham in the same county. 

The vertebra differs much in form from other species here described, and though absolutely larger than those of 
T. neocaesariensis, the neural arch was not coossified with the body, indicating the immaturity of the individual. 

The body is but slightly concave between the planes of the parapophyses, which are not at all directed down- 
wards ; the latter are very short, and their articular faces are directed posteriorly and outwards anteriorly, the 
posterior portions being connected by a high crescentoid ridge r whose anterior margin approaches within three lines 
of the rim of the articular cup ; behind, a weak median keel connects it with the body plane, which is succeeded by 
a prominent tuberosity close to the posterior shoulder. The anterior parapophysial articular surface extends without 
constriction to the rim of the cup. The floor of the posterior half of the neural canal is broken away, revealing a 
wedge-shaped chamber, which extends posteriorly and outwardly nearly to the shoulder. 

In. Lin. 
Total length, 2 10. 

Length to shoulder, 2 3. 

Width of cup, 1 8. 

Vertical diameter of cup, 1 6.75 

" " to edge of parapophysis, 2 

"Width between parapophyses near cup, 1 10. 

" " " at posterior angle, 2 1. 

Length from post, angle parap. to shoulder, 1 1.25 

Length from post, angle parap. to cup, 1 2.5 

The radii of the median area of articulation are numerous, 1,34), fine and equal ; the transverse rugae of the 
anterior area are also fine, thirteen in number. 

Portions of femur, tibia, humerus, and ribs were in the same lot with the above described vertebra; they 
resemble the cervical vertebra in color and in the bright green of the matrix which adheres to them externally, as 
though they had been wet ; their size relates so as to render their appertainance to the same animal probable. They 
indicate an animal of large size. 

The shank of the femur is cylindrical at its middle ; the prominence of the anterior flexure is situated well below 
the head, while the head itself is not as broad as in some species (e. g. Crocodilus tiporcatus). An obtuse ridge 
runs from behind forwards and downwards across the outside face of the shaft, transferring the position of the 
steepest face from the back to the front aspect. On the inner face the trochanter is small, and the surface is swollen 
near the upper edge at the flexure. 

Compared with the shank of the femur of Hyposaurus rodgersi, the present is less depressed and lacks a longi- 
tudinal concavity, with obtuse elevated margins, near the superior flexure, which is characteristic of that species. 
For a considerable proximal portion of the femur, the medullary cavity is quite small ; at the middle it is much 
larger, and the walls quite thin : measurements are, 





















Length of portion of femur, 

Largest diameter below head. 

Convex extent of head, 

Circumference of shaft, 

Diameter of tibia two inches below head, 

Length of condyles of humerus, 

Diameter of inner condyle, 

" region between condyles, 

" shaft 2.5 inches above condyles, 

Greatest diameter of head of rib, 2 

Second — A fifth cervical, two lumbars and fragments of long bones from Birmingham, N. J. The cervical is con- 
siderably larger than the last, and has the arches coossified ; its total length is 34^ lines, and is appropriate to the 
adult condition of this animal. The lumbars indicate further the difference between this species and the Hoi. 
obscurus. The cups and shoulder are more expanded latterly than in any species here enumerated, even near the 
sacrum, and the centrum more depressed, and with concave sides. A very obtuse rib extends along the inferior 

Total length, 3. 85 

Length to shoulder, 2.3 

Width of cup, 1.76 

" shoulder, 1.76 

Both of these specimens represent the Crocodilus basitruncatus of Owen, and should 
their reference to the Bottosaurus by Leidy prove erroneous, will indicate a species under 
that specific name. 

From the Cretaceous greensand of New Jersey. 

HOLOPS, Cope. 

This genus, which appears to differ from Thoracosaurus only in the absence of lach- 
rymal fossae, has probably been represented by several species during the Cretaceous period 
in New Jersey. Vertebrae of two species have been described by Leidy as pertaining to 
the genus Crocodilus. All of them differ from the species of the existing six genera of 
Crocodilidse in the absence of elongate hypapophyses on the cervical vertebra?, and their 
replacement by bified or simple often transverse tuberosities. As observed by Leidy, the 
T. macrorhynchus from the cretaceous of France presents a similar character. 

The student should also notice that in this genus the axis is the longest vertebra, and 
the third cervical the most constricted. The third cervical vertebra, as well as the axis, is 
also in Alligator mississippiensis and Crocodilus biporcatus slightly more constricted 
than the succeeding vertebra. The cups widen above to the fourth dorsal ; from 
this point to the sixth the centra narrow rapidly, presenting more difference than in the 
same distance elsewhere. The eighth begins to widen again, though still narrowed. 


The lumbars grow widest as respect the centrum, to the sacrum. The two sacral vertebra? 
are the broadest and most depressed and their cups and balls are flattened. 

The parapophyses rise from the atlas till they stand truncated above by neurapophysial 
suture on the fifth dorsal. On the sixth dorsal they stand just above the suture, and on 
the seventh on a level with anterior zygapophysis (H. brevispinis). Among modern Croc- 
odiles, Caimans and Gavials, Cuvier found hypapophyses on the anterior five or six dorsal 
vertebrae ; on the Holopes and Thoracosaurus these processes are visible on the eighth, 
and probably on the ninth in H. brevispinis Cope. 

The teeth in this genus are much curved. They have long conic crowns with minute 
lateral cutting edges and minute stria? of the enamel, but no proper ridges as in Hypo- 
saurus. The teeth in T. neocaesariensis are blunter than in the others. In the H. 
glyptodon, the teeth are coarsely fluted, and the surface everywhere, finely and sharply 

As the vertebrae of the species of this genus are very numerous, and the crania are 
usually much mutilated before coming to the hands of students, I give a synopsis of their 
characters, including those of Thoracosaurus and Bottosaurus. 

I. Cervicals with deeply bifid hypapophyses, and transversely oval cup. 
Dorsals with transverse oval cups. 


II. Cervicals with short united transverse hypophyses, slightly bifid posteriorly; 
anterior extremities more or less quadrate. 

Smallest species, vertebra? 1 6 lines long (-without ball) ; cups of all transverse oval. 


Large ; dorsals about third and fifth, with snbcordate outline and thin margins ; i. e., 
widened above, narrowed below, wider than deep ; centra 20-25 lines ; cervicals with 
subquadrate cup. 


Large, centra 20-25 lines long ; dorsals about seventh, etc., much compressed ; cups 
deeper than wide, third and fourth regularly round or oval, not cordate, with thick lips ; 
cups of cervicals round or transverse oval. 


III. Posterior cervicals with hypapophyses scarcely traceable, and well separated. 
Large species ; dorsals near seventh, with transverse oval cup, with thick margins ; 

cups of cervicals subquadrate, bodies little keeled below ; centra 20-25 lines long. 



IV. Cervicals with a thick obtuse transverse ridge connecting parapophyses in place 
of hypapophyses. 

Large; cup quadrate. bottosaurus harlaxi. 


TJioracosaurus brevispinis Cope. Proceed. Acad. Nat. Sci., Phila., 18G7, p. 39. Geological Survey N. Jersey, 
Appendix C. 

The specimens on which this species are established are, a cervical vertebra in the Museum of the Academy of 
Natural Sciences, procured by Timothy A. Conrad at St. George's, Delaware, and one cervical, six dorsal, four 
lumbar, one sacral and four caudal vertebrie from the Greensand of Burlington County, N. J., which have been 
liberally placed at my disposal by the Burlington Comity Lyceum of Natural and Civil History. The last series 
is from the same individual apparently, and is more complete than that of any other cretaceous Crocodile hitherto 
brought to light. Also on a seventh dorsal, two lumbars and a humerus from the marl excavations of Samuel Engle, 
near Medford, Burlington County, New Jersey. 

The last are from an adult, while the more perfectly preserved is not fully grown, since the neural arches of many 
of the dorsal vertebra have separated at their sutures, yet its approach to maturity is indicated by the persistence of 
this arch of the third cervical, of some dorsals, lumbars and caudals. The species is the smallest of the genus, and 
will furnish reliable date for the estimation of the dimensions of other extinct croeodilia. The vertebrae are relatively 
more slender than those of the Alligators, and the general proportions are more probably those of the T. neocae- 
sariensis and of the Gavials. This will give a basis of estimation for the head and tail. 

Length of cervical series, 7.75 

" dorsal " 15. 

" lumbar " 6.25 

" sacral " 2.33 

Total body, 31.33 

Caudal series (part estimated), 35. 

Head (estimated), 13. 

Total, 6 ft. 7} inches. 

Cervical vertebra;. — Characteristic of the two of these before us, is the deep concavity of the inferior aspect of the 
centi-um with only a trace of a keel, and the steep elevation of the same surface to the rim of the articular cup. The 
latter does not form a well defined ridge, but rather a plane, connecting the anterior extremities of the parapophyses, 
which, in the sixth, supports two short accuminate hypapophyses. In both cervicals the parapophyses look outwards 
at right angles to the centrum, but as in existing species, possess shorter articular surfaces on the third, whose 
body is also rather more elongate behind them. In the sixth, which will be typical of the posterior four of the series, 
from the crest of the posterior shoulder to the posterior outline of the parapophysis, is one-half the distance from the 
latter point to the margin of the anterior cup, and somewhat less than the articular face of the parapophysis. The 
posterior shoulder is elevated in both, and the articular globe is contracted and projecting. 

The vertical diameter of the neural canal of the third is four-fifths the same as the anterior cup. The latter is 
small, its vertical diameter being only double the depth of the osseous elevation between the parapophyses. The 
neural spine is little elevated, compressed, its anterior margin subacute, and obliquely turned backwards to a 
posterior apex. 



r n. 













Third cervical, total length, 

Crest of shoulder to outer angle parapophysis, 

Last point to plane of cup rim, 

From middle hall to apex neural spine, 

Least width of base of centrum, 

Sixth cervical (larger individual), length, 

Vertical diameter between rims of cup, 

The expanded bases of the neurapophyses leave only the cariniform epapophysis between them. 

Dorsal vertebral. — The first, third and fourth with the parapophysis on the centrum have lost only their neural 
arches. The parapophyses have convex articular surfaces, which have a very posterior direction and are followed by 
a deep depression in the side of the centrum ; in the first they are a little behind the middle of the side of the body. 
The hypapophyses of all are distinguished by their lack of compression and their obtuseness. They are directed 
vertically downwards, the anterior face posteriorly. That of the first is bifid as broad as long, the others simple, 
longer than broad on the third. They are preceded by a depression behind the rim of the cup, and succeeded by 
a second, simple, small hypapophysis near the shoulder, which is finely many-grooved ; it exists as a trace on the 
third, which of all the dorsals, may alone be said to present a very obtuse carina below. The surface in the first 
three is striate next the rim of the cup ; on the shoulder on the first two. The sixth dorsal is more compressed and 
smoother : its cup is more produced upwards and outwards, while that of the first is more nearly round, and the 
others are intermediate. 

The articular cups of dorsals near the seventh and eighth are nearly round, slightly deeper than broad. The. 
horizontal width of the diapophyses is considerable, and the transverse extent of the articular (inferior) surface of 
the posterior zygapophysis is equal one-half the length of the centrum between shoulder and cup. 

The seventh dorsal of the adult is perhaps twice as large as the above, without being half as large as the same 
in the H. obscurus. Though the centrum is as much compressed as that of the sixth, the cup is still broader than 
deep vertically. The centrum has a lateral longitudinal obtuse ridge. The hypapophysis is remarkably large for the 
position in the vertebral column. It is trigonal in profile with truncate planes before and behind, the anterior 
concave. The costal articular face is half way to the extremity of the diapophysis on its anterior margin. It is 
transverse, not vertical as in the sixth in II. tenebrosus. 

Sacral. — The first exhibits a longitudinal concavity on the posterior half of the centrum below. 

Caudals. — The body of an anterior caudal is not compressed, those of three others, but slightly so ; the 
cup of the first is round ; those of the others deeper than broad. Three have stout diapophyses ; of these the two 
posterior have a concave inferior face separated by a strong angle from the sides, while there is an additional lateral 
angulation on the anterior part of the side of the more anterior. In the two anterior, the neural spine is twice 
constricted from base probably to near apex, leaving an anterior laminiform portion, and a median much stouter. In 
the caudals the suture of the neural arch is much obliterated. 

Measurements of Vertebra). 
Of Adult. 
Seventh dorsal ; total length, 

depth articular cup, 

longitudinal width neural arch (greatest), 
" " diapophysis, 

Of Young. 
Sixth dorsal ; total length, 

length to shoulder, 

depth neural canal to eud . hypapophysis, 

" articular cup, 
width " " 





















Measurements of Vertebra. 
Of Young. 
Eighth? dorsal; total length, 

length to shoulder, 

longitudinal line between zygapophyses, 
horizontal base of neural spine, 
depth of neural canal, 
" " articular cup, 
width of " " 

neural suture to nearest diapophysis, 
Thiid? lumbar; total length, 

length to shoulder, 

longitud. line between zygapophyses, 
horizontal base of neural spine, 
depth neural canal, 
" articular cup, 
width " " 

First sacral ; length, 

anterior width centrum, 
posterior " " 

depth neural canal, 

" articulation of diapophysis, 
length " " 

width neural arch between diapophyses, 
Anterior caudal ; length, 

" to shoulder, 
depth neural canal, 
" articular cup, 
width " " 

width inferior plane, 
Distal caudal ; length, 

" to shoulder, 
depth cup,* 
width " 
length base diapophysis, 

None of the vertebra exhibit a constriction of the neural canal by a ridge on each of its sides, as is seen in the H. 

This specimen is named from the short longitudinal and vertical extent of its hypapophyses. 

A right humerus accompanying three vertebras of the adult, has the same color and mineralization, and was 
found with them ; it probably belongs to the same animal. Compared with a humerus of H. obscurus of medium 
size, it is three-fifths the length and has more strongly marked articular faces. The head is more transverse, less 
rounded, and more strongly divided into the scapular and coracoid faces. The width of the head is one-fourth the 
length, and reaches the summit of the deltoid crest. This crest is lower down in H. obscurus, the above width only 
reaching its proximal base. The anterior face above the crest is concave in H. brevispinis, nearly flat in H. obscurus. 
There is a moderate internal tuberosity distally, and the condyles are moderately prominent. Coronoid fossa well 

* Heasuremeuts of the articular cup are always made from middle to middle of the rim. 


















































In. Lin . 
Length, 6 8. 

" to middle of deltoid crest, 1 8.5 

Width of head, 1 7. 

" shank at middle, 8.5 

" condyles, 17.5 

A mass of induarted marl, with vivianite and oxide of iron from Monmouth County, N. J., submitted to me by 
Prof. G. H. Cook, contains the posterior part of the cranium of this species, with cervical, dorsal, lumbar and caudal 
vertebras, dermal plates and coracoids. The individual was immature, as shown by the non-anchylosis of the centrum 
of the atlas, the neural arches, etc. 

The cervical has the small hypapophysis composed of two small separated tubercles slightly prominent. The 
dorsal, with a prominent hypapophysis which is trincate in front and at the end, has the round cup characteristic of 
this species and the H. tenebrosus. The dermal plates are large, elongate-quadrate, considerably exceeding the 
frontal region in width. Their fossae are in some deep, wider than the interspaces, in others smaller, the plate with 
a broad smooth bevelled border. 

The cranium exhibits the specific and generic characters very well. The muzzle is broken off at the anterior 
extremity of the pre-frontal bone, showing that there is no foramen as in Thoracosaurus. The acute posterior 
extremities of the nasals remain. At the anterior border of the orbits the lachrymal is wider than the pre-frontal, 
and the pre-frontal wider than the frontal. 

The pre-frontal suture does not extend further back than opposite the middle point of the diameter of the orbit, 
No part of the orbital margins are everted, except for a shorter distance on the malar bone. The temporal or crota- 
phite fossae are of about the same area as the orbits. The width separating them is very little less than one-half the 
distance between the orbits. The anterior wall of the foramen is not quite vertical as in H. tenebrosus, nor very 
oblique as in another species. The sculpture is less marked than in the latter, and though it would become perhaps 
more profound with age, it is quite different in pattern from these. There are small pits near the orbital margins, 
and shallow grooves which incline backwards towards the median line, which is almost smooth. There are no grooves 
or pits on the interparietal region. In H. obscurus there are large deep pits all over the frontal, which is concave, 
and broad smooth margins and a median line of pits on the parietal bone. In the the third species (figured by Leidy 
Cret. Rept., II., 8,) the pits are more numerous and the interparietal wider, and with marginal grooves. The ante- 
rior face of the crotaphite fossa is very oblique, or thickened inwards below, while it is vertical in the H. 

Postfrontal Frontal Parietal 

suture, width, width. width. 
H. brevispinis, .52 1.23 .6 

H. obscurus, .8 2. .55 

H. ?sp., .7 1.95 .08 

The surfaces of the malar, postfronto-parietal and post-temporal arches are marked with distant shallow pits. 
The superior concealed insertion surfaces of the supraoccipital are largely exposed, and rugose. 

The basioccipital, sphenoid and pterygoids are more or less exposed. The first is vertical, with latero-inferior 
processes directed upwards. The sphenoid has a very narrow exposure, but this is horizontal. The posterior-inner 
processes of the pterygoid lie closely appressed to the sphenoid and basioccipital laterally. This arrangement is much 
as in the living Gavialis gangeticus. The posterior nares are more anterior, however, and the septum not completed. 
Their plane is perhaps a little above that of the orifice of the eustachian tubes. The lower extremity of the basi- 
occipital, has a well-marked posterior keel. 




Length (median above, ) to apex prefrontal, 5.5 

" (axial) to front of orbit, 4.15 

" " " crotaphite foramen, 2.2 

Width between extremities quadrata, 6. 2 

" " postfroutal angles, 2. 

" muzzle at point frontal, 3.32 

Length dermal scutum, 2 .3 

" cervical vertebra (to ball), 1.7 

Width crotaphite foramen, 1.7 

This species furnishes the generic characters. I have not been able to ascertain the non-existence of the pre- 
frontal foramen in the following species, but as they bear more resemblance in the cranial sculpture and in size to 
this species, than to Thoracosaurus neocaesariensis, I refer them at present to Holops, 


Of this species I have only two cervical, two dorsal, and three lumbar vertehrae of one individual, all in a good 
state of preservation. They present characters similar to those of H. obscurus in the cervical vertebra, and inter- 
mediate between those of that species and the H. tenebrosus in the dorsals. While the fifth dorsal in the forrner is 
deeper than wide in its articular cup and slightly quadrate, the present species presents a broadly cordate cup to the 
fifth, narrowed below, yet considerably wider than deep ; the H. tenebrosus presents a regularly round or transversely 
oval cup in the same position, much as in H. brevispinis. The accompanying cut exhibits the difference between 
this species and the H. tenebrosus. The cordate form is distinct on the fourth dorsal, where in H. obscurus the cup 
is regularly oval. The cervicals are not different from those of H. obscurus, except that the cup is rather more pro- 
longed below, or subquadrate. 

The cervical vertebrae referred to this species may be known by the outlines of the anterior extremity outside the 
cup, of which the latter partakes, which is between quadrate and cor- 
date ; by the distinct inferior concavity between the parapophyses, and Fig. 18. 
by the gradual but complete lateral eversion of the latter. In the 
types the posterior shoulder is remarkably prominent. The inferior 
carina is little marked on the fourth, while the hypapophyses are 
small and united. In a fifth, judging from the more posterior position 
of the parapophysis, it is formed of two partly confluent subacute 

The dorsal vertebras, from their nimeralization, condition, and 
time and place of discovery, probably belong to the same animal as the 
cervicals above described. The breadth of the cup of the fifth is a 
little greater than the length to the posterior shoulder, it differs from 
Leidy's figure of the sixth of tenebrosus, T. III., f. 13, in its large 
hypapophysis, which stands on nearly the entire centrum, and is very 
prominent, and concave in front ; the sides of the centrum are concave 

from cup to shoulder. In the third dorsal but a narrow space exists behind and before the hypapophysis. and the 
vertical diameter of the cup is less than the transverse, and exhibits the same cordate outline. As usual some (the 
anterior) lumbars are deeper than wide, and in others the bodies are subquadrate in section, and the transverse 
diameter of the cup greater. Measurements are as follows : 



Third cervical : length to shoulder, 

" " " opposite posterior angle parapophysis, 

" " width between latter points, 

'' " least width behind parapophyses, 

" vertical diameter cup, 

" transverse diameter cup, above, 

" below, 

Fourth cervical : length to shoulder, 

" " " end parapophysis, 

Third dorsal : length to shoulder, 

" " " opposite posterior angle parapophysis, 

" " " of basis of hypapophysis, 

" " width between ends of parapophyses, 

" " " of neural arch just behind diapophyses, 

" " " of anterior cup, 

" " " of neural arch, 

" vertical diameter neural arch, 

" " " cup, 

Fifth dorsal : length to shoulder, 

" " " basis hypapophysis, 

" " width of centrum at middle, 

" " " cup, 

" " vertical diameter at middle, 
Lumbar : length to> shoulder, 
" vertical diameter cup, 

" transverse, 

Portions of the frontal and parietal bones of a gavial are figured by Leidy (III., fig. 8). They are shown under 
the head of H. brevispinis not to be referable to the cranium of that species, or of H. tenebrosus ; whether they can 
be referred to H. obscurus, H. cordatus, or H. glyptodon is as yet uncertain. 

This species is no doubt a gavial-like animal, very near the T. obscurus. It is sufficiently different in vertebral 
structure ; probably other differences will be found where other bones are known. 

Tlioracosaurus glyptodon Cope. Geol. Survey of New Jersey, Appendix C. 

This species is indicated by a few teeth only, but they are of so marked a character as to render their recognition 
and arrangement proper. 

The best preserved specimen indicates a slender, subcylindrical strongly curved crown, with the acute ridge 
which divides the planes extending to its base. There are probably nine obtuse ridges on the inner or concave face, 
each about as wide as each interval. Both ridges and grooves are covered with sharp fine longitudinal striae, which 
are continually interrupted and irregular. 

The pulp cavity, as on others of the genus, is rat her small. Length of crown, 12 lines ; diameter at base, 4.5 1. 
The apex is slightly compressed and smooth. In an older specimen the minute striae are less distinct, leaving the 

From Barnesboro, Gloucester Co., N. J. Not found with or near any of the preceding specimens, but with 
dermal plates not distinguishable from those of H. obscurus. 






































Thoraco&aurus obscurus, Cope, Geol. Surv. N. J., App. C. C'rocodilus obscurus, Leidy, Smitbson. Contrib , 1 -0 j, 
p. 115. Tab. II, fig. 4. Undetermined crocodile; teetb tab. I, f. 7, 8, 9. 

Tbis species was established by Prof. Leidy on vertebra? from Barnesboro, Gloucester Co. and Arneytown, Bur- 
lington Co., New Jersey. I bave procured numerous vertebra; from the former locality, which were associated with 
a cranium, which was nearly destroyed before reaching my hands. Enough, however, has been preserved to indicate 
with certainty that it is agavial, and probably of the same genus as that to which Cook's Monmouth County skull 
belonged. Numerous dermal plates were procured at the same time, which however are not more certainly to be 
ascribed to the T. obscurus than to the T. tenebrosus, of which several portions were discovered in the same excav- 

The vertebra? from Barnesboro in my possession have apparently pertained to two individuals ; two cervicals, a 
second and fifth dorsal, with six other dorsals and lumbars and a caudal, of the one, and a first and fifth dorsal with 
eleven other dorsals and lumbar vertebra?, of the other individual. 

In addition to these, I have examined two cervicals found with muzzle and long bones at Barnesboro ; a fine 
series of vertebra? and other bones in the Museum of the Academy from near Birmingham ; three fine series in 
possession of Prof. G. H. Cook,f the Mount Holly Lyceum Natural History, and Prof. O. C. Marsh of Tale College, 
all from Birmingham ; portions of two individuals in my own collection from the same place, and a set of eight verte- 
bra? from Mullica Hill in my possession. Numerous other specimens of this species have fallen under my examination. 
Hence it is obvious that this is the most abundant gavial of tire New Jersey Cretaceous. 

A series of cervicals from Birmingham is instructive, showing the differences in the characters of the respective 
vertebra?, The axis, which as usual is coossified with part of the body of the atlas thereby much increasing its 
length, has parapophyses represented by two crests directed downwards and separated by a deep longitudinal cavity; 
they are united in front. An obtuse ridge on the side of the centrum separates two longitudinal concavities. The 
third cervical is also deeply concave below, since the parapophyses descend much below the plane of the centrum, 
and are united by an arched connection in front, which is not separated from the rim of the cup. As usual the para- 
pophyses continue to rise, till on the sixth they are a little above the plane of the centrum. They also become more 
posterior, till on the sixth their centre is opposite the middle of the centrum without ball : on the seventh this 
point is behind the middle. The first dorsal is readily distinguished by the small size and posterior direction of the 
articular face of this parapophysis ; its middle is a little below opposite the middle of the cup. On the third dorsal 
the same point is just above opposite the middle of the cup. 

On the fourth cervical a trace of median inferior keel exists ; it is quite strong, but thin and concave on the fifth, 
while on the sixth it is thicker, and does not separate deep concavities, but only slightly concave planes. It is still 
more elevated on the seventh, and increases beyond. On the third there is no distinct hypapophysis. On the fourth, 
a transverse elevation on the anterior arch connecting the parapophyses marks it ; on the next it appears in the same 
place as two small longitudinal tubercles with groove between. On the sixth they are similar but stronger. Ou the 
seventh it is much more elevated, the groove between its halves being now a transverse plane. On the first dorsal it 
is a simple, large process, extending over half the centrum with a small knob behind it : on the third it has a longer 
base, but on the second the longest, extending the whole length of the centrum. On the fifth it is thick, with 
rounded edge below, and with a truncate triangular face in front. It is apparent on the eighth, as an obtuse eleva- 
tion in front. 

From the fourth posteriorly the characters are drawn from other series, which show many of these vertebrae. 

The cups of the third to fifth cervicals look a little more truncate below, owing to the prominence of the trans- 
verse ridge. They are almost perfectly round thence to the second dorsal, where the transverse diameter begins to 
exceed the vertical a little. First on the fifth dorsal the cup assumes some of the narrowed form of the centrum. 

The very numerous lumbars present nothing peculiar. As in other species they are more or less striate grooved 
at the bases of the cups and balls. 

The series first mentioned as from Barnesboro presents typical characters of the cervical hypapophyses. 

t The types of T. obscurus preserved in the museum of Rutgers College have been kindly placed in my hands by John Smock, Asst. State Geologist 


It is in the third a short acute transverse crest truncate in front, gradually inclined behind ; fourth, a similar crest 
curved into a crescent quite as in Leidy's plate* above cited under T. obscurus. In the fifth they are two weak 
elevations, much less marked than in the above in my possession. All the above exhibit a well marked constriction 
between the parapophyses and the rim of the cup. The dorsals with hypapophyses are distinguished by the less 
cordate form of the articular cups, they being relatively broader below, and in the second to fifth, narrower above 
than in the T. cordatus. Their neural arches have on the inner faces a ridge constricting the neural canal slightly. 
The hypapophysis of the two-fifths in my possession are rather short, broad and obtuse. 

The cervicals may also be known by their strong posterior shoulder, and constriction of the body behind the para 
popbyses, where the width enters the length (exclusive of ball) twice: the relation is 1:1.5 in T. neocaesariensis. 
The parapophyses are most abruptly turned out, and are directed downwards, thus embracing a median concavity 
which is divided by a rather narrow carina. Separated from the rim of the cup by a narrow transverse plane, a hypa- 
pophysial elevation extends transversely between positions in front of the parapophyses: this is less elevated medially 
than exteriorly, the latter position being marked by a prominent angle. 

The articular cup of the first dorsal is a slightly transverse oval. The lumbar vertebrae exhibit little to distinguish 
them from those of other species. An anterior caudal is more depressed than that from near the same position 
in T. brevispinis. The cup is broader than high, and the inferior plane broad and concave. 

Fifth cervical ; total length, 

length to shoulder, 
width of neural canal, 

'■ between ends diapophyses, 
" " " parapophyses, 

lateral depth of body in front, 
median " " " 

depth articular cup, 

»f C( cc 

Seventh dorsal ; total length, 
■ length to shoulder, 

width neural canal, 
depth anteriorly, with hypapophysis, 
width of cup, 
depth " 
Posterior dorsal ; length to shoulder, 

vertical diameter cup, 
transverse " " 

The mandible preserved, indicates an animal of considerable size. Estimated according to the proportions of 
existing Gavials its length would have been : — 

Head, 28.70 

Body, 92.85 

Tail, G9.64 

































Total, Ft., 15 ; In., 11.19 

In. Lin. 
Length of mandible preserved, 13. 

" symphysis, 11.5 

" splenial in front of fork, 4.6 


I I 

Width at anterior point of splenial, 
" near extremity, 
" an inch behind fork, 
" between rami at same point, 

Teeth opposite symphysis, 







The larger teeth are all broken, but one with fang exposed, would probably measure when complete 1 in., 10 lin. 
The form of some of the smaller is well represented in Leidy's figures above cited; they are acuminate, strongly 
incurved, of a full lenticular section, with an anterior and posterior raised cutting ridge, in the transverse plane of 
the crown. The sides present numerous narrow weakly defined facets, and are in a half protruded one, finely striate. 
The alveoli do not open on the horizontal plane of the inside of the mandible, but the latter is raised above them 
for the posterior half of the symphyseal portion of the jaw ; the latter is more depressed towards the extremity. 
Teeth from other specimens and localities exhibit marked characters. They are all much curved and slender conic, 
and subcylindric ; the tip smooth, the remainder more or less extensively minutely striate, but not fluted or ridged. 
The fang is slightly flattened. In T. neocaesariensis the crowns are relatively shorter, less curved and more obtuse; 
in both the anteroposterior dividing ridge is well marked. Part of the teeth attributed by Leidy to Hyposaurus 
belong here ; see synonymes. 

The muzzle of a larger individual from Birmingham, accompanied vertebrae of this species, with a smaller gavial 
cranium in fragments ; and a cervical vertebra similar to that described under Bottosaurus harlani. Its reference to 
this species is not certain, but I give a figure of itr. 

The lateral maxillo-premaxillary suture is not preserved, so the number of prem axillary teeth cannot be exactly 
ascertained; there are four to the line of the posterior margin of the large incisive foramen, of which the anterior is 
quite small. The posterior palatal suture of the same element is prolonged in a narrow chevron on the median line 
below, to opposite the eighth alveolus from the front ; there are nine alveoli behind this point, to the broken 
extremity. A noteworthy character consists in the presence at the posterior part of the series of deep fossae 
between the maxillary alveola; for the reception of the mandibular teeth, showing that the latter did not project 
externally between the former, as in the existing gavial. The same structure appears in the smaller cranium which 
accompanied it,* but is not found in the Thor. neocaesariensis. 

Fig. 19. 

Fig. 20. 

♦The fronto-parietal reeion of this one is described under head of n. brevispints. 


Measurements. In. Lin. 

Length of muzzle to 16th tooth, 1G 0.5 

" " " extremity of premaxillary bone, 7 1. 

" " " to posterior edge incisive foramen, 2 4.5 

" to anterior " " " 1 7.5 

Humerus. — This, with a femur, belongs to the right side of the series from Birmingham, first described. Its 
characters are indicated under the head of T. brevispinis. The shaft is rather slender and curved outwards ; the 
head is strongly curved backwards ; its articular face is narrow, and remarkably convex. The condyles are broken 
away, leaving the comencement of the coronoid fossa : 

In. Lin. 

Length (restored), ■ 9 5 

" to summit deltoid ridge, 2 11 

Width head, 2 3 

Circumference shaft (least), 2 1 

Femur. — This piece is perfect ; two distal ends from Barnesboro, besides numerous proximal ends, have also 
come into my hands. It is more slender than in the caimans and crocodiles of the present day. The inner trochanter 
is quite prominent, the articular face of the head very convex. The shaft is sigmoidally bent anteroposterioly, and 
is bowed extero-internally, with a subordinate abrupt incurvature below the head. The latter is largely caused by 
a prominent thickening on the inner side. The outer condyle is twice the size of the inner, and they are continued 
into obtuse crests on the upper face of the bone, of which the outer is much more elevated. Below their sides spread 

In. Lin. 

Length, 10 7 

" of head (straight), 2 7 

" (transverse) of condyles, 2 3 

Least circumference of shaft, 3 5 

Of dermal bones, those of two species, perhaps of more, were procured from the excavations that produced four 
species of Gavials, with Bottosaurus,* and to which they are to be referred is not very clear. In the one, the pits 
or fovea are very large and are separated by narrow elevated partitions ; in the other they are small and are separated 
by fiat intervals wider than themselves. In the former the fovea extend to the edges of the plate on the bevelled 
edges; in the latter, the bevelled edges are without fovae. Leidy says of those of this type, "plates coarsely 
foveated." The first described belong to the median series of the present species, as they usually accompany its 
bones when they occur alone; and the latter to the external series. 

Parallelogrammic dermal bones without pits, and with very high longitudinal crests, standing on more than half 
the length, frequently accompany remains of this species. They are cervical or nuchal bones, and are of relatively 
large size, equalling those of the dorsal region. The crests are oblique in the direction of their length. Such bones 
belong to this species, perhaps to H. cordatus also. 


Crocodilus ienebrosus, Leidy. Cretaceous Reptiles U. S., 115. Tab. III., figs. 12-15. Thoracosaurus Ienebrosus 
Cope. Geological Survey of New Jersey, Appendix C. 

This species is as yet little known. Leidy'stype is represented by two cervicals, a seventh dorsal, a caudal, and 
portions of humeri ; on account of their close resemblance, and marked specific separation from H. obscurus, I regard 
as the same an animal of which a cervical and three lumbars are preserved in my collection. The dorsals exhibit a 

* Several simple coprolites which accompanied these remains, probably belonged to the same species. 


round cup -with thick edges. In the cervicals the hypapophyses are represented by rudimental elevations separated 
by a space, except on the third, where there is the usual anterior cross ridge, followed by a concavity. I refer here a 
dorsal, kindly lent me by Prof. Marsh, where the cup is more transverse oval than in T. obscurus. 

The lumbars from Barnesboro are characterized by a form more slender than those of the T. tenebrosus, more 
nearly resembling some from the series of T. obscurus. Measurements of : 


Fifth cervical : length to shoulder, 21 . 

" posterior angle parapophy sis, 15. 
" anterior " " 6. 

width to posterior angle parapophyses, 19.25 

" behind the parapophyses, 13.25 

" of cup above, 15. 

" vertical diameter cup, 15.25 
" neural canal, 8. 

Lumbar : length to shoulder, 24. 

vertical diameter cup, 18. 

width of " " 17. 
" neural canal, 5. 

" basis of neural arch in front, 15. 

Specimens of an adult from the pits of the West Jersey Marl Co., near Barnesboro, Gloucester County. 

Cretaceous Reptiles, Smithson. Contrib., XIV., 5. Pr. Ac. N. Sci., Phila., 1852, 35. 

This genus adds to the characters of Holops, a pair of large prefrontal foramina 
similar to those characteristic of Teleosaurus, and Plesiosaurus. The other cranial char- 
acters, as well as the vertebral, are very different from those of Teleosaurus, which is 
amphicoelian, and are rather those of the existing Gavialis. The teeth and cervical 
vertebra?, however, differ from those of the latter genus. 

"What is not seen in Gavialis or Holops is the character here presented, of a strong 
septum dividing the posterior nares most completely; the latter open inferiorly and oppo- 
site the hinder part of the crotaphite foramina. 

A species, the T. macrorhynchus, occurs in the cretaceous of France, as observed by 


Leidy. Smithsonian Contributions, XIV., 1865, 5. Tab. I. 

Gavial Dekay Ann. Lye. N. York, 1833, 156. Tab. III., fig. 7-10. Gavialis neocaesaricnsis'De'kay. Zool. New 
York, 1842, pt. III., 1844, 82. Crocodilus s. Gavialis clavirostis Morton. Proceed. Acad. Nat. Sci., Phila.. 1^44. 82. 
Giebel Fauna v. Vorvelt, 1847, 122. Crocodilus basifissus Owen. Journ. Geol. Soc, London, 1849, 381, Tab. X., 
f. 1, 2. Palaeontology, 1860, 277. Pictet Traite de Palaeontolgie I., 1853, 482. Crocodilus dekayi Leidy. Journ. 
Acad. Nat. Sci., II., 135. Sphenosaurus Agassiz. Proceed. Ac. N. Sci., Phila., 1S49, 160. Thoraeosaurus grandis 
Leidy. Proc. A. N. Sci., Phila., 1852, 35. 

Cretaceous limestone of Vincentown, Blackwoodtown, and Big Timber Creek ; sandstone of Navesink ; green- 
sand of Blackwoodtown, Barnesboro, and Monmouth County, New Jersey. 


Several individuals of this, the largest of our cretaceous species, have been found, but only fragments preserved. 
The cranial bones are smoother than those of the species of Holops, and the posterior nares are separated as above 
mentioned. The cervical vertebras of this species are distinguished among those of its congeners by the lack of 
inferior concavity, breadth of basal carina, complete bifurcation of low hypapophyses, and posterior and transverse 
position of parapophyses. 


Journ. Geol. Soc, London, V., 383. 

This genus is as yet the only known representative on this continent of the Amphi- 
coelian Crocodiles. It belongs, says Owen, to the Teleosauridae, from which the great 
size of the parapophysis distinguishes it. Its remains are quite abundant in the New 
Jersey cretaceous ; stratigraphically its position is the latest of its family. Thoraco- 
saurus being the earliest of the Procoelian Crocodilia, the interesting spectacle is pre- 
sented of the coexistence in America in large numbers, of two types which, in the old 
world, are separated by the whole period between the Jurassic and Tertiary. 

As might be supposed then, there is some approximation in structure between these 
two extreme genera of their series. The hypapophyses of the cervical vertebra in Thor- 
acosaurus are of the Teleosauroid type. Both are. alike slender-nosed genera, as I have 
been able to ascertain for the first time for some of them. 

As a Teleosaurian reptile the bassioccipital does not present the vertical position usual 
among the Procoeli, but is horizontal. The sphenoid is also more horizontal in its expo- 
sure, and much wider, and with a straight anterior margin, not incised to accommodate 
the posterior nares. The frontal bone is marked with longitudinal shallow grooves. 

The teeth of Hyposaurus are more compressed than in the last genus described, some 
of them are from the shortening of the crown almost triangular in outline, but most are' 
elongate ; the enamel is thrown into a Tew fine continuous ridges. 

The cervicals may be distinguished from those of the other gavials of New Jersey, in 
addition to the form of the articular faces, by the earlier appearance of a strong keel-like 
hypapophysis, that is, on the fourth of the series ; at first it is most prominent at the 
anterior end. 


Loc. Cit. Leidy, Cretaceous Reptile 3ST. Am., p. 18, Tab. Ill, 4-21. 

Vertebra. — The neural spines of the cervical vertebrae are acuminate, of considerable — finally, of great — height, 
the anterior standing transversely on the neural arch, the median subtetragonal, the posterior, as usual, 
longitudinal in section. In an anterior cervical vertebra, length 2 in., the spine is 2 in. 10 1. above the ceiling of 
the arch, and is acute ; it receives a strong lateral wing from each posterior zygapophysis, which does not disappear 
till near the tip. These enclose a deep groove on each side behind, with a strictly perpendicular posterior median 


rounded rib ; in front a narrow keel extends from the tip to the neural canal ; the lateral ake are curved backwards. 
On a more posterior cervical, the lateral ate are very heavy, short and rounded, and enclose no groove with the 
slightly projecting posterior vertical rib, while the anterior keel has become a strong compressed wing, dividing two 
shallow anterior grooves ; breadth and length equal iu section. In a last cervical, length 2 in. 12 1., the longitudinal 
section (equal about an inch) is longitudinal cuneiform, owing to the projection of the anterior ala. In an anterior 
dorsal the section is longitudinal (1 in. 5 1.); the lateral ribs remain at the base only, and the posterior carina is 
strong and sharp ; it is acuminate, and was probably subacute, but is broken at tip ; if restored would measure 4 in. 
6 1. at least. 

Humerus. — This element is relatively much shorter than in Thoracosaurus or modern Crocodilia : it is also stouter 
and more curved than these, and furnished with very largely developed deltoid crest and condyles. One specimen 
accompanying femur from the same — the right side, and many other elements from near Birmingham, Burlington 
County, N. J., have been submitted to me by Prof. Cook. 

The condyles are deeply divided, and project far before the coronoid fossa, which is little marked. The shaft is 
nearly cylindric, strongly arched backwards. The groove bounded by the deltoid crest is very deep. A portion 
between the head and the crest is lost. The former is truncate above, with a very oblique coiacoid face. The 
medullary cavity is very small. 

In. Lin. 
Total length (restored), 10 

Length from condyles to deltoid crest, G 7. 

" across head (straight*, 3 2. 

" across condyles, 3 0.5 

Least circumference of shaft, 4 2. 

Femur. — The shaft of the femur is a most characteristic piece from the greensand of the Eastern States. It is 
rather more than usually flattened intero-externally, and at the point of insertion of the adductor muscle is trilateral 
in section from the elevation of the ridge of insertion, and the depression of the antro-inferior face into a shallow, 
longitudinal concavity. The ridge and the surface behind it are rugose. The shaft below and up to the head is 
longitudinally concave on the inner side, plane on the outer. The articular face of the head has a remarkable antero- 
posterior extent, and is more obliquely produced upwards and forwards, in relation to the longitudinal axis of the 
shaft than in the other species. To support it the end of the shaft is turned forwards and strengthened by thickness, 
having a flat anterior face not seen in other species, and the articular face is bent downwards at right angles to it, 
and to the course of the longer posterior portion. It is here widest also. This form gives an unusual anteroposterior 
range of motion, and is appropriate to a powerful swimmer. The insertions for powerful muscles would indicate 
the same. 

The condyles of this femur are lost. 

The teeth have some resemblance to the Polyptychodons in their strong ridges, but they have distinct anterior 
and posterior cutting edges, dividing a larger external from a smaller internal surface, the anterior turning in towards 
the latter, near the base of the crown. The section of the base of the crown is a broad oval, tip more compressed and 
worn obliquely outwards by use. Internally eight, externally eleven strong, but fine ridges extending over the usual 
half or two-thirds, alternating with shorter ones ; all obsolete at base anteriorly. The color of the two teeth is 
black at base, ochre at tip ; between, lined by both colors. 


Total length tooth, 22. 5 

" crown, 9. 

Diameter antero-posterior at base, 4. 

These teeth are in the alveolae of a distal portion of the maxillary bone, 4 in. long. Three in. one line includes 
three alveolae, measuring between margins. The muzzle has been here very slender, as the measurements show, 
made at the posterior tooth ; the anterior teeth issue successively higher up, and above the palatine plane. 



Width of palate, 18.5 

Height of os maxillare at middle, 14. 

Thickness of palatine suture of o. maxillare, 2.5 

Cretaceous Green Sand of New Jersey. 

Spec. nov. 

This small species seems to he clearly indicated by a portion of the ramus mandibuli containing three and half a 
fourth alveoli, and two perfect teeth. These parts are less than half the size of those of the smaller individual of H. 
rogersi, whose maxillary hone and teeth are described in the preceding article. The crowns of the teeth are shorter 
and more compressed than those in the corresponding part of the jaws in H. rogersi ; they are marked with a coarse 
obtuse fluting to near the tip, with a finely striate enamel as in Holops glyptodon ; in those of H. rogersi, the enamel 
is smooth and ridged by fine keels, which do not extend more than half the length of the crown. 

That the animal of which I describe this fragment was not the young of the larger Hyposaurus, is, I think, 
indicated by the deep grooving and strong ridging of the dense layer of bone of the ramus ; by the minute pulp 
cavity of the crowns of the teeth, and by the well developed successional tooth in the fang of one of the latter, whose 
apex has nearly reached the alveolar margin. That the individual is not fully grown is probable, but that it is of 
smaller species than the H. rogersi, there appears to be little room for doubt. 

The ramus is scarcely flattened below, as is the case with most gavials, and the depth at the symphysis is equal 
the width of each ramus. Sculpture in deep longitudinal grooves slightly inosculating. Teeth directed very little 
outwards : their fangs and crowns are considerably compressed ; the antero-posterior cutting edge is stronger than 
the ridges, and does not diminish to the base of the crown. Viewed from within the form is symmetrical and 
straight ; from behind their crown is greatly incurved. The outline of the crown from within is an isosceles triangle, 
the width, more than .66 the height. Ribs on the inner face, seven, on the outer, eight. A few teeth in the jaws 
of H. rogersi are as short and broad as those here described, but they are not found in the middle of the series as in 
this species, but probably belong in the posterior alveoli, as occurs in some alligators. 


Length of fragment, 19..3 

Width at middle, 6. 
No. of alveolae in an inch : three and half and interspace. 

Length tooth above alveolus, 4. 

" crown of tooth, 2.75 

Width " " at base, 1.75 

From the middle Green sand bed at Birmingham, Burlington, Co., N. J. Presented to the Academy by Judson 
C. Gaskill. 


The following species probably belongs to the Amphicoeli, but to what genus cannot well be determined, as 
nothing but the teeth are known. 


Trans. Amer., Phil., 1860, p. 146. Tab. 
Bad Lands of the Judith River, Nebraska. 




Proc. Acad. N. Sci., Phila., 18G8, p. 203. 

Characters. — Toes 5 — 4, with claws two-three. No osseous nasal septum or bony eyelid. Belly protected by 
series of osseous plates, as well as the back. 

All the genera of Crocodiles hitherto known as living, are characterized by the possession of three claws on 
the fore-foot. The present therefore offers a remarkable exception. The free fingers and half webbed toes, and the 
bony abdominal buckler, together with the cartilaginous nasal septum, are points of strong resemblance to Jacare 
(Gray including Gaeman Gray) but it differs from these creatures in the lack of bony orbit. In specific characters it 
differs from those of this genus which it most resembles — as J. nigra, in the absence of a transverse bony ridge 
between the orbits. Another feature of importance is the relation of the canine teeth of the lower jaw to the upper. 
On one side this tooth is received into a notch as in Crocodiles, on the others, it enters a pit of the maxillary bone, 
within the border of the same as in Alligators ! This remarkable combination may be abnormal even in this species, 
but this cannot be now ascertained, as it rests at the present time on a single specimen only. As its affinities are 
rather more Alligatorial, I am disposed to anticipate that the dental arrangement of the latter animals will be most 

Fig. 21. 

Fig. 23. 


Fig. 24. 


Char, specificus. — Nuchal plates in a cross row of six ; cervicals in four cross-rows, all of four plates except the 
last of two. Dorsal plates in six — in a few eight in each transverse row. No posterior crest on arm or leg. Tail 
short with remarkably low crest. Muzzle broad flat, without any ridges ; its width at the eighth tooth entering 1.4 
in length from end muzzle to anterior margin of orbit. 

Description. — The specimen in the Museum of the Academy is young, measuring only 2 feet 5 inches in length. 
Of this the skull measures to the margin of the supra-occipital 2 in. 10.5 lihes ; and the tail to the vent 13 in. 7 liu. 
From groin to heel 3 in. 2.5 lin., and the hind foot 3 in. 7.5 lin. The muzzle is a broad ovate, the sides rather more 
convergent anteriorly than in the Alligator mississippicnsis. There is a thickening in front of each orbit, and 


between them on the middle line another which together enclose two shallow concavities. Superciliary margins 
raised, the cranial table quite flat. The margin of the quadratojugal bone projects strongly. The scales of the 
limbs are all smooth, and those of the dorsal region with very low keels. The sides have four longitudinal rows of 
ovate scales separated by scarcely defined smaller ones. The abdominal plates are longer than broad, and are in 
twelve longitudinal rows. Dorsals in seventeen transverse series from interscapular to crural region. The lateral 
crests of the tail are only obtuse keels ; they unite on the thirteenth annulus behind the vent inclusive. Color above 
dark brown, almost black on the upper surfaces of the head. The tail is paler, of a light olive brown. Lower sur- 
faces everywhere bright yellow, including the entire lower jaw and margin of the upper. Eyelids and a band through 
ear yellow, the former with a black spot above. 

Remarks.- — This interesting addition to our knowledge of the Reptilia was made by Schulte Buckow of New 
York, while on a visit to the interior part of the course of the Magdalena river in New Grenada. This naturalist 
has also enriched our collections with other interesting vertebrata of that region, both living and dead. 


Proceed. Acad. Nat. Sci., Phila., XII, 550, 1860. Halcrosia, Gray Ann. Mag. Nat. Hist., 1862, 273. 

As this genus has been variously understood, since its first publication, I take the present opportunity of quoting 
the original description, and adding such observations as are necessary to a full comprehension of the species 
embraced by it. 

" Osteolamrus, Cope, was characterized as a genus of Crocodiles presenting several points of analogy to the Alli- 
gator. The nasal bones were prolonged anteriorly, and uniting with the short spine of the intermaxillary, divided 
the external nasal orifice, as in the genus Alligator. The eyelids were entirely osseous as in Caiman. There was no 
transverse bony ridge between the orbits. The dermal plates upon the tail, extremities, and the thorax, were more 
or less completely ossified ; upon the gular region the ossification was most complete, the shields having a coarse 
natural articulation. 

"The digits of the posterior extremity were very slightly webbed. 
" Cervical plates distinct from the dorsal. 

"Mr. Cope alluded to the remarkable extent to which ossification was carried in this genus. The cranium was 
much more rugose and pitted than in the adult specimens of much larger species, and the crotaphite foramina were 
roofed over by bone. The latter peculiarity was sometimes observed in the genera Jacare and Caiman. 

"The osseous gular and thoracic buckler was also similar to that exhibited by those genera, and by the 
extinct "Crocodilus" Hastingsise Owen, the existence of which has been shown by Professor Huxley. 

" Two specimens were exhibited : one a skin brought from the Ogobai river, Western Africa, by Mr. P. B. Du 
Chaillu ; the other, the skull of a half grown individual, obtained from the Museum of the Pennsylvania University, 
"These Mr. Cope regarded as belonging to a species hitherto unknown, and which he proposed calling Osteolae- 
mus tetraspes." 

Several descriptions of species of this genus have been published under different names. It is a matter of 
question whether all do not relate to one species. A young one was described by Murray, whose muzzle was of course 
much broader in relation to its length than in the adult. An adult was afterwards described by Lilljeborg with the 
relatively longer muzzle. It differed from that described by Murray in having but four rows of dorsal shields, and 
but two pairs of cervicals ; in the latter there are three pairs of cervicals and six rows of dorsals. My type specimen, 
brought from the Ogobai by DuChaillu possesses six rows of dorsals, and only four cervicals, thus combining the 
characters of the two. Gray, however, who has seen Murray's type, says there are but four rows of dorsal plates ; 
in the Ogobai specimen one row has but five, and in three others the two outer are nearly united ; so I am disposed 
to think that no great importance is to be attached to this character. Murray's specimen has the relatively enlarged 
brain cavity of a young animal elongating the table of the cranium ; Lilljeborg' s, which is adult, maintains this 
character more than our specimens do. Gray gives a figure of the cranium of the adult, which coincides with two 
crania in our Museum, one of the above mentioned specimen, while both agree in the proportions of the muzzle with 
that described by Lilljeborg. The last, however, differs from all these in having the table of the cranium but little 



Fig. 26. 

wider than long ; in our specimens and Gray's figure it is nearly twice as wide as long. It also appears that the 
nasal bones do not entirely divide the nasal meatus, which they do in the three specimens under observation. On the 
whole I am disposed to think that these forms belong to one rather variable species. It is true that Gray says "hind 
foot fringed," but this I am inclined to think must be true to a very limited extent. There is only a keel in our 
specimen, and Lilljeborg says there is no fringe in his. 


Proceed. Ac. N. Sci., Phila., 1860, 550. 

Crocodilus palpebrosus, var. 2, Cuvier. Oss. Foss. iii., t. 2 f. 6 (part). 
Crocodilus trigonatus (part) Curvier. Oss. Foss. iii., 65. 

African Black Crocodile, Gray. Eept. British 
Assoc, 1862, Zool. Section, 107. 

Osteolaemus tetraspes, Cope. Proc. Acad. N. 
S., Phila., xii., 550. 

Crocodilus frontatus, A.Murray. Proc. Zool. 
Soc, 1862, pp. 139, 213, fig. head, t. 29, by Ford. 
Strauch, Syn. Cro., t. I., head (young). 

Halcrosia frontata, Gray, Ann and Mag. Nat. 
Hist., 3d series, X., 277. 

Halcrosia afzelii Lilljeborg. Proceed. Zool. 
Soc, Loudon., 1867, 715. 

Habitat, Gaboon Ogobai (Duchaillu). 

Calabar (Murray), Sierra Leon (Afzelius). 

This species was originally characterized as 
follows : . 

Proportions of the head somewhat similar to 
those of Crocodilus trigonops, Gray, of India. 
Breadth of muzzle at ninth tooth equal to the dis- 
tance between the external nasal orifice and anterior border of the orbit, and to the width of the table of the 
cranium posteriorly. A short ridge in front of each orbit, directed obliquely inward. 

Teeth }|, rather compressed. Four nuchal shields, in a single transverse series ; four cervicals in pairs ; Dorsal 
shields in six rows. Posterior extremities without fringe. Total length of the entire specimen, five feet. 

In addition to the characters given above maybe mentioned the strong concavity of the muzzle in the longitudinal 
direction, and the prominence of the nares. The margins of the maxillary are very sinuous, being much contracted 
behind the fourth and eleventh teeth. The derm of the head is thin and corneous, and divided into many segments, 
which have a fine sculpture of straight lines radiating from the centre in each. The bones of the cranium are very 
strongly pitted. Seventeen transverse series of plates between nape and posterior line of femora, 12 to union of 
lateral caudal crests, and 19 from that point to end of tail. Nineteen cross-rows of large plates from ankle joint to 
groin, on anterior face of limb. Counting similarly on the fore limb, there are 13 series. Only the two lateral dorsal 
keeled ; keels of the outer of the first eight caudal annuli, low. 

Color everywhere black ; the plates occasionally with irregular olive lines. The young, according to Murray, 
have olive bands on a yellow-brown ground, including two bands of plates, and separated by two bands. Total 
length, five feet ; muzzle to supraoccipital ridge, 8 in. 9 lin. ; do. to posterior margin thighs, 2 ft. 7.6 in. 

Gray supposes this to be the " Crokodil noir du niger" of Adanson, and hence cites as its earliest name Croco- 
dilus niger Latreille. Dr. Strauch, however, shows that this is probably the Crocodilus eatapJiractus Cuvier, and I 
have pointed out that it cannot be the species of Latreille. 



The ilium extended horizontally forwards, and supporting a number of vertebrae 
anterior to the two sacrals of other Reptilia. Acetabulum perforate, and partly en- 
closed peripherally by the ilium and pubis. Pubes elongate, parallel ; ischia longitudinal, 
in plane of ilium, elongate, with distinct head for pubis. Femur with transverse neck and 
head, and third trochanter. " Cervical and anterior dorsal vertebra? with par and diapo- 
physes, for articulation with bifurcate ribs." Neural arches of dorsal vertebra; attached 
by suture ; of sacrals, shifted over the intervertebral sutures. 

The structures presented by the Dinosauria have presented greater difficulty of expla- 
nation than any other type of extinct vertebrates.* This has in part resulted from the 
attempt so assign them to types already known, and to explain their structures in accord- 
ance therewith ; a course scarcely consistent with our present knowledge of the peculiari- 
ties of the parts themselves. The type is a good illustration of the necessity of 
interpreting extinct forms by a combination of the " law of successional relation," with 
" the law of types " or of morphological " correllation," and not by either alone. 

The direction assigned to pubes in this order, is suggested by considerations explained 
below. They have probably diverged forwards and downwards from the vertebral column 
and their great length indicates a prominent abdomen.. The only Dinosaurs where they 
are preserved in place, the Stenopelix valdensis of Von Meyer, and Compsognathus 
longipes of Wagner, justify this proposition. The ischium in Stenopelix and Teratosaurus 
is a broad flattened bone slightly curved in the lateral direction, and of sufficient strength 
with its fellow, to support the weight of the animal when in a sitting posture. The 
pubes in Hadrosaurus and Compsognathus are much more slender and proximally dilated ; 
as in the Crocodiles the chief support of each is derived from the articulation with an 
anterior tuberosity of the ischium. The articulation with the ischium is probably wanting 
or very slight and ligamentous, and the acetabulum was thus open, a large foramen being 
included by the three bones which usually compose it. 

The head of the femur is transverse to the direction of motion of the condyles, and 
not oblique as in modern lizards. Hence the motion of this element was in a line paral- 
lel with the axis of the body, and the limb could not be directed obliquely from that axis 
so as to allow the body to rest on the ground between them in the ordinary progression of 
the animal, as is the case with Iguanas, Crocodiles, etc. 

The fore limbs appear to have been weak, even when somewhat elongate, as in 
Iguanodon. Their articulation with the scapula is a singular part of the structure. In 

* For discussions of these relations see Proceed. Ac, Nat. Sci., Phila., 1866, 317, and Proceed. Amev. Philos. 
Soc, 1869, 16. 


Iguanoclon and Hadrosaurus there is a very small sphaeroid condyle on the inner side of 
a broad proximal extremity. If the condyle only articulated with the scapula, the rota- 
tion of the humerus would be very limited; if the long narrow proximal articular surface, 
which is the whole of the flattened proximal extremity of this bone the rotation would be 
still less. In Laelaps however I find no round condyle, only the long narrow articular 
face of the proximal extremity, as in the Crocodiles. This would not allow of abduction 
and adduction, but as in the bird, of only flexure and extension. This is readily seen in 
the movements of the Crocodile. I suppose the anterior limbs were more useful as sup- 
ports when these animals placed the head near the ground, than for any other purpose, 
especially in Laelaps and its allies. 

The character of the articulation of the vertebral column by intervertebral discs, the 
double headed ribs, the elongate sacrum and large medullary cavities of the long bones 
have been cited by Prof. Owen in evidence of the Mammalian tendencies of the animals 
of this subclass. Their reptilian features, the single occipital condyle, quadrate and 
coracoid bones, with the median tarsal ginglymus, are equally shared by the Aves, though 
most of the usual distinctions between the latter class and the Reptiles hold good here 
also. Prof. Owen also points out a special bird-like tendency in the alternation instead 
of superposition of the neural arches of the sacrum on their centra ; and other points can 
can now be added. Thus the reduction of the metatarsals to three in some of the genera, 
and their close approximation and excess of length over the phalanges, brings to mind 
these bones in the penguin. With the same reduction follows the confluence of the first 
series of the tarsal bones, and the great diminution of strength of the fibula and its close 
application to the tibia ; the front limbs are much reduced, and the long bones more pneu- 
matic. In the most extreme form in this direction known, the first series of tarsal bones 
is entirely confluent with the tibia as in the birds, the three metatarsals are much elon- 
gate, the cervical vertebrae increase in number, and the pubes assume a position at right 
angles to the vertebral axis, which is intermediate between their anterior position in most 
Reptiles, and their posterior, in Birds. 

These features indicate three perhaps suborders, which are defined below. 

Quite as important, as indicating the avine affinity and remarkable character of this 
order, is the evidence derived from the pelvis. And first, the support of this arch, the 
femur, has been already alluded to. The head and neck of this bone are at right angles 
to the direction of the condyle. In other reptiles the axes of these are oblique to each 
other, so that the femur does not move in the direction of the axis of the body, but. 
obliquely to it, thus permitting the body to rest on the earth. In the present, case the 
structure is the same as in the birds and Mammals ; the femur could only move in a plane 
parallel with the axis of the body. The reduced length of the fore limbs of many Dino- 


sauria, renders it impossible that they should have reached the ground, in progression, if 
the posterior were at all extended, and suggests that these reptiles walked erect. That 
this was the case is demonstrable from the materials at our disposal, I am inclined to 

The ilium, instead of having a vertical position as in reptiles, is longitudinal as in 
birds. That is, the small process which, in Lacertilians and Crocodiles, projects in advance 
of the acetabulum, is largely extended and developed, while the lower extremity of the 
posterior, or principal portion, is raised anteriorly, so that the two together constitute an 
elongate element, embracing not only the two posterior or original sacral vertebra?, but 
a considerable number anterior to them. The effect of this is to diminish the proportionate 
number of lumbar or dorsal vertebra?, to increase the length of the consolidated sacral 
series, and to throw the acetabulum, and consequently the femur farther anteriorly, and 
also farther upwards, than in the ordinary reptiles. All these features are characteristic 
of the birds, and have direct reference to an upright position. Thus it is readily per- 
ceived that the consolidation of the sacrum, is related to the need of a greater strength of 
support at a single point; its length, and that of the ilium, to the throwing forwards of 
that support to beneath the centre of gravity of the animal's body. 

The very elevated position of the acetabulum, and consequently of the usual point of 
support of the pubes, renders it in the highest degree improbable that the latter bones 
had the usual direction and position seen in the reptiles. That is, an anterior position 
would not allow of space for the enlarged visceral cavity which these creatures probably 
possessed. But it is obvious that in most of the Dinosauria, if not in all, the pubes were 
not supported in the same manner as in most Reptiles. In Hadrosaurus and Iguanodon 
there appears to have been absolutely no point of union between ilium and pubis, and in 
Teratosaurus and Megalosaurus that union, if existing, must have been very slight. The 
ischia of Stenopelix, Hadrosaurus, and Iguanodon furnish the substitute for this, in an 
anteriorly directed process for the support of the pubis, a feature otherwise characteristic 
of the Crocodilia only, among reptiles. 

I conclude, therefore, that the pubes were not directed forwards and that they were 
not directed backwards either, in those forms at least, where there is no preacetabular sup- 
port for that bone. They must therefore have been directed downwards, and this is the 
position they have in the extreme avine form Compsognathus. 

Such ischia as we are acquainted with, are of a remarkably elongate form, simulating 
those of birds rather those of reptiles, and indicating clearly the existence of a great pelvic 
visceral cavity. 

From these considerations as to the extent of the pelvic elements we derive further, that 
the visceral cavity was mainly supported by them and that it was transferred so as to be 


posterior to its position in ordinary reptilia. This, taken in connection with the anterior 
position of the support of the body — the femur, rendered the erect progress of the Dino- 
sauria possible. 

Another approximation to the birds will probably be found in the sternum and 
coracoids. These elements are but little known, and that imperfectly ; the best example 
has been furnished by the great Teratosaurus suevicus Mey. Here, according to Plienin- 
ger, the elements corresponding to the xiphisternum of Lacertilia is a large thin shield- 
like bone, of elongate form. The coracoids are narrow, prismatic bones, and abut against 
the anterior angles of the xiphisternum ; being entirely different from the broad flat 
element of the Lacertilia and other orders, which are usually extensively in contact with 
each other or. with the xiphisternum. 

We have, however, among Dinosauria, as among Quadrumanous Mammalia, a series of 
forms, from those constantly assuming the prone Lacertian position, to those that walked 
exclusively erect like birds. Perhaps the most Lacertilian form known is the genus 
Scelidosaurus of Owen : the greater equality in length of the limbs, and the numerous 
toes, as well as lacertilian dentition assign it to this place. Then we find forms like 
Iguanodon and Hadrosaurus, the most gigantic of land animals, where a semi-erect atti- 
tude was the natural one, as they like the Megatherium and Megalonyx, lived on vegeta- 
ble food, and were necessitated to raise themselves on their hinder limbs to reach it. Here 
the bird-like type is approached, in the reduction of the metatarsi to three, and the great 
antero-posterior extent of the ilium. In the genus Laelaps the position was probablv 
quite erect, and additional resemblances to the ornithic type are adapted to large animals 
no longer requiring a vegetable diet, but procuring their living food by activity and 
strength. They are accordingly organized so as to be entirely independent of extraneous 
support, and furnished with great powers either of running or leaping. 

Intermediate between this extreme, and the type of Ignanodon, comes a large carniv- 
orous genus, the Megalosaurus of Buckhmd, the representative of types like Laelaps, in 
the old world. In its longer fore limbs it differs from the most bird-like forms. A car- 
nivorous type only known from teeth, is Aublysodon Leidy ; it is American. 

The other herbivorous species, of less size than Iguanodon, which was furnished with a 
dorsal series of dermal bones, is the Hylaeosaurus armatus Mantell, found in the Wealden 
of England ; while an allied form which was covered with long massive dermal spines, 
has recently been discovered in the same formation in the Isle of Wight, and referred to 
the genus Polyacanthus Owen. 

The sizes of the best known species of these genera are as follows : 



Length ft. 
Polyacanthus, Owen, 9 

Scelidosaurus harrisonii, Owen, 12 

Iguanodon anglicus, Meyer, 28 

Hylaeosaurus armatus, Mant, 21 

Hadrosaurus fonlkei, Leidy, 28 

Poecilopleurum bucklandii, Deslong, 25* 

Megalosaurus bucklandii, Mant, 1 30* 

Laelaps aquilunguis, Cope, 24 

Teratosaurus suevicus, Meyer, 1 30 

Ornithotarsus immanis, Cope, % 35 

Prof. Owen suspects the animals of this order to have had the septum of the ventricles 
of the heart complete as in the Crocodilia. It is an interesting inquiry whether there were 
two aorta-roots or only one, and if one, whether the right or left remained. I have little 
doubt that the Dinosauria further resembled Crocodilia in having the lateral lobes of the 
cerebellum developed, and the vermis plicate. 

The affinity to the modern Sauria, or Lacertilia, which some authors have allowed of, 
is very slight ; the Crocodilia, though somewhat removed, are the nearest Jiving allies. If 
we consent to a derivative relation between types, we must consider this order to have given 
origin by divergence and metamorphosis to both the Mammalia and Aves. The structure 
and embryology of the last two classes forbid the idea that either could have been derived 
from the other. 

Besides the differences in the structure of the tarsus and metatarsus observed in this 
order, there are marked differences in that of the tibia. Thus most of the order present a 
very prominent spine and Crest, of bird-like character ; but Plateosaurus Meyer and Tera- 
tosaurus Meyer both Triassic genera, appear to possess this character in a very slight 
degree, the former scarcely at all. I have, therefore, not included them in the groups 


Cope Prcc. Acad. Pliila., 1S66, 317. Therosauria Haeckel, 1861 

Proximal tarsal bones distinct from each other and from the tibia, articulating with a 
tibia and with a terminal face of a well developed fibula. The ilium with a massive 
narrowed anterior prolongation. 

In the few genera of this suborder, of which the teeth have been discovered, a successive 
divergence from the type of the Goniopoda is visible, in the shortening and increase in 

* These estimates I have reason to think exaggerated. 


number of the metatarsals. Thus so far as known, according to Owen, Hylaeosaurus 
Mant. had three closely approximate metatarsals. In Hadrosaurus they are elongate, but 
their number is unknown. In Iguanodon, Owen represents a fourth, but nidi mental 
metatarsal, the hind foot being still three-toed, while in the more ancient genus Scelido- 
saurus, the same authority gives four shortened metatarsals, of which the smallest supports 
a digit ; and a fifth rudimental metatarsus, which supports no digit. In Stenopelix there 
appear to be five digit bearing metatarsals according to Von Meyer. 
This order is then probably divisible into the following families : 

I. Teeth in several rows forming a vertical pavement ; metatarsals "? three. 


Embracing the genus Hadrosaurus, Leidy. 

II. Teeth in a single row, cutting ; three digit bearing metatarsals. 


Genera Iguanodon Buckl. Hylaeosaurus Mant. 1 Palaeoscincus, Leidy. 

III. Teeth in a single row, cutting ; four digit bearing metatarsals. 


Genera Scelidosaurus, Owen. Stenopelix Myr. (Heeth). The last named genus is 
known from a single skeleton, in which according to Von Meyer, the sacral vertebras are 
aU distinct. It is perhaps an immature individual. 


Proc. Ac. Nat. Sci. Phila., 1858, 218. Cretaceous Reptiles N. Am., 7G. Trachodon, Leidy, L. C. 1S56. ? Thes- 
pesius, Leidy 1. c. 

This genus embraces at least two species which are among the most gigantic terrestrial 
animals of which we have any knowledge. They represent the Iguanodon of the old 
continent, whose species is similar in bulk. The two genera, however, differ in many 
details. The teeth, as above noted, are different. The spines of the dorsal vertebrae, 
instead of being flat anteriorly, are smaller and slender subcylindric. 

Most of the characters of this genus have been given by Leidy in his description of 
H. foidkii. I add a more complete examination into the characters of the scapular and 
pelvic arches, which are but lightly treated of in the " Cretaceous Reptiles of N. America." 

Scapula. — Here may be introduced a description of certain massive bones of two indi- 
viduals of a species of Dinosaur. I had formerly admitted the possibdity of their 
pertinence to the pelvis of Hadrosaurus, but the discovery of that element in the H. 
foulkei, indicates that another place must be sought for them. 



Pig. 27. There was when the bone was complete, a 

double head, the anterior or superior apparently 
for articulation with the coracoid ; the inferior, 
to receive the proximal end of the humerus, 
whose condyle is adapted to it both in size and 
shape. It is a flat bone curved in the direction 
of its plane, which is vertical, and narrowed 
distally, where it is broken off. It is expanded 
proximally into two heads of which the support 
of the inferior is in the general plane, while that 
of the superior is obliquely transverse to that 
plane : this head, which I believe to be the 
anterior and attached to the coracoid, is broken 
off. The inferior articular face is slightly con- 
cave ; it is rugulose for an articular cartilage, 
and its plane is exactly transverse to the long 
axis of the bone. Its form would be vertically 
oval but for an expansion on what I suppose to 
be the outer side. The inner side is characterized by an obtuse longitudinal ridge, which 
extends upwards and backwards from the anterior head and soon disappears. A simi- 
lar ridge is seen in the ischium of Crocodilia. As this ridge disappears from the inner 
side, a- more obtuse one appears on the outer, and is in line with the subtransverse expan- 
sion of the neck of the anterior head ; it soon reaches the posterior margin of the bone, 
which it thickens. Between this point and the posterior head, the margin is thin and 
acute. A more imperfect specimen of the same element from the same side (the right) of 
a rather smaller individual exhibits similar characters. 

As compared with the scapula of Iguanodon, Hylaeosaurus and Scelidosaurus, a strong- 
resemblance is seen in the marked distinction of the outline of the glenoid cavity, and the 
existence of a large distal depression of a subtriangular form. The anterior expansion is 
broken away, but from the indications at the fracture was probably well developed. 

The proportions of the larger scapula indicate a gigantic animal fully equal to the 
known Hadrosauri ; the humeral support agrees with that bone in the latter. The 

dimensions are as follows : — 


Length of fragment on posterior margin, 1 3.9 

Depth proximally (greatest), 7.2 

" distally, 4 



Depth of glenoid cavity, 

Width " 

" " anterior expansion, 
" " fractured end, 






Another fragment of an animal of dimensions similar to the last was found at the same 
time and at or near the same place, (Freehold,) in Monmouth county, New Jersey, but 
cannot be associated with the above described scapula, as neither the place nor time of dis- 
covery can be ascertained with sufficient accuracy. It appears to be the glenoid cavity of 
a scapida from which the blade has been broken off, and from which a short subconic 
procoracoid projects. The accompanying cut and measurements will furnish the requisite 
information respecting it. 

Fig. 28. 

Length from a to b, 

" " b to c, 

" d to e, 

" e to f, 


The fragment may belong to Mosasaurus. 

Pelvis. — There is much difficulty in determining the true relations of the pelvic ele- 
ments of these and other Dinosauria, owing to their unusual forms, our imperfect materials, 
and the discrepancies between authors. 

Ilium. — One of our best clues is the skeleton of the Iguanodon discovered at Maid- 
stone, and preserved on a block of rag, which has been described and figured by Professor 
Owen. The bones mostly preserve a normal though much disturbed relation to each 
other. An examination of the figure and description strongly suggests — 

First, that the hooked superior prolongation of the ilium is the posterior, not the an- 
terior, as described by Owen. This is confirmed by Owen's figure and description of the 
ilium and sacrum of the same species in Wealden Reptiles, PI. III. (Iguanodon), where 
the thick hook-like process with its abrupt descent to the acetabulum, is also posterior. 

• The structure of Hadrosaurus, in which both caudal and lumbar vertebra? have been 
discovered, proves that this relation is the true one. The caudals have a greater trans- 
verse diameter than the lumbars, which are comparatively quite contracted from side to 
side. This is the reverse of what is usual among reptilia, where the caudals are usually 



the most contracted. The wide caudals continue without contraction to the point where 
the tail reaches the ground. They then begin to elongate. The anterior vertebrae thus 
form a massive column, which no doubt supported the weight of these monsters. That 
the ischia performed this function in part in Lselaps, is evident not only from their more 
massive structure, but from the more elongate caudal vertebrae, while the still more slender 
caudals in the known Triassic genera, adds to the evidence derived from the ischia as to 
their use. 

In the ilium of Hadrosaurus the slender hooked process and the expanded tuberosity 
both exist, and I am disposed to place the former posteriorly, and the latter anteriorly 
and externally as the most probably correct relation. This, moreover, throws posterior to 
the acetabulum, the more elongate articular face, where one might look for the ischiadic 
suture with propriety. This arrangement, however, presents the apparent anomaly of 
position, that the planes of the inner faces of the ilia are made to converge instead of di- 
verge, thus rendering the interiliac cavity remarkably narrow. There can, however, be 
no doubt that this is really their position in Iguanodon, judging from Owen's figures 
(above), III. and IV., and that the sacral diapophyses really rest on the convergent faces 
of the ilia, whose planes are directed inwards as well as downwards. This adds still fur- 
ther to the peculiar ensemble of characters of these Dinosauria. 

This relation has already been described as the true one, by Leidy. 

The anterior prolongation of the ilium in Hadrosaurus appears to be less slender and 
more plate-like than in Iguanodon and Scelidosaurus, where it is remarkably produced. 
Nevertheless, in the accompanying cut, the restoration (by Dr. Horn) of the anterior por- 
tion may be too much dilated, and is probably not long enough. 

Pubis. This element of Hadrosaurus has never been described. I believe that I find 
it in a proximal portion of a large bone, which occupies this relation very appropriately. 
Its proximal superior subtriangular articular face is naturally associated with the already 
assumed anterior articulation of the ilium, and when so placed, presents outwards the 
smooth articular surface of the anterior part of the acetabulum. . It also presents forwards 
a narrowed process, and in line with the same posteriorly, a broad, vertical plate which is 
soon broken off, but which I suppose to have been continued but a short distance. The 
posterior process I suppose has been continued as the support of a slender pubis,* conform- 
ing in this respect to the type of birds. That there is very little trace of articulation for 
ischium behind the acetabulum is obvious, so that it is to be supposed that this element 
was small, vertically dilated proximally, and in contact with the pubis at the superior 
processes on the supero-external margin of the latter. 

* A suspicion which I at one time entertained, that the so-called pubis of the Crocodilia was homologous with 
the marsupial bones, has been removed, by reading Rathke's posthumous work on the development of the Crocodile. 



Length iliac face pubis, 

Width " " " 

Entire depth, 

Width pubic process where broken, 

anterior process where broken, 
" acetabular face, 

Fig. 29. 







Ossa ischia. These lateral elements are not very different from those identified bv 


Owen in Iguanodon with clavicles, and by Leidy in Hadrosaurus with the pubes. The 
Director in the British Museum has well pointed out the possibility of such a form of 
clavicle being probable, after a comprehension of the variations presented by the modern 
Sauria, and the not dissimilar form in Trachysaurus and Cyclodus. Leidy, however, is of 
opinion that similar bones in Hadrosaurus resemble rather the pubic bones of Iguana, and 
calls them pubes, with doubt. The writer sees a much greater resemblance between them 
and the elements called ischia by Wagner in the Compsognathus, and which are homolo- 
gous with the posteriorly directed bone so called in birds. 

It is noticeable that in the great Dinosauria the supposed clavicles do not diminish in 
length in the same proportion as do the humeri, as one would be led to expect were they 
clavicles. The relative lengths in three species are as follows : — 


Iguanodon anglicus ; humerus, 85. 

os ischium, 29. 

Hadrosaurus foulkii ; humerus, 22.5 

os ischium, 27. 

Laelaps aquilunguis; humerus, 12. 

os ischium, 20. 

Their density and strength in the last named species are not readily reconcilable with 
the needs of such small fore limbs. Further, in Stenopelix Myr. and Compsognathus, 
where similar elements exist in the position of pubes and ischia, no clavicles have been 
preserved to us. 

The more or less normal position in which these bones were found in the Maidstone 
specimen of the Iguanodon, as given in the figure accompanying Prof. Owen's monograph, 
has been already alluded to ; the ilia were lying parallel with each other, their extremities 
similarly directed. The ischiadic bones lay across the ilia in their axes, the anterior dilated 
extremities lying not far from the position of the lost pubes, the posterior directed far be- 
hind the iliac crests, parallel to their axes. The similarity of position in both, and the 
preservation of relation between many of the other bones, renders it probable that their 
identification with ischia also indicates their natural relation. 

The direction of the ischia is a difficult point to determine, but may be best understood 
by reference to those of Megadactylus and Clepsysaurus. In Hadrosaurus (see Leicly's 
plate in Cret. Rept. U. S.) this bone consists of a long slender subcylindric shaft with 
dilated extremity. The dilated portion thin, a part in line with the shaft and truncate, and 


separated by a concave margin from a larger portion at right angles to the shaft. The 
latter bears an oblique surface for fixed articulation at its extremity. 

In Megadactylus,* the distal portions of the ischia are united on the median line for a 
considerable distance, and are styloid in form. This portion is evidently distal, from the 
lack of articular faces and the divergence and flattening of the other extremities. They 
also resemble the distal extremities in Compsognathus. In Clepsysaurus, the shaft and di- 
lated extremity are both preserved. The former resembles that of Megadactylus, the latter 
that of Hadrosaurus in some degree. If the shaft be posterior, the other extremity is an- 
terior, and the larger dilatation extending at an angle to the shaft supports, no doubt, the 
iliac articulation. The trihedral shaft indicates a median line of junction. In Hadrosau- 
rus no part of the shaft presents a face for contact with that of the other side, while in 
Laelaps such face is very distinct and elongate. From the above, I suppose that the larger 
extension of the ischium is superior and bears the iliac articulation, that the concave an- 
terior outline is that bounding the acetabulum, and that the lower dilatation was in con- 
tact with but not united to the pubis. Thia is the more probable, since it agrees nearly 
with the arrangement in Iguanodon, as pointed out by Huxley. t It cannot be denied, how- 
ever, that the supposed iliac articulation in the ischium in Hadrosaurus, bears a remark- 
able similarity to the median suture presented by the union of the two supposed ischia on 
the middle line below and distally, as in the pubes of Struthio. In that case, they would 
be pubes. In a posterior direction and median approximation it will agree also with the 
known pelvic elements of an interesting Saurian described by Von Meyer (Palaeonto- 
graphica) from the Wealden of Germany, the Stenopelix valdensis. No attempt has been 
made, so far as I am aware, to refer this animal to its place. It appears to me in its ver- 
tebral and pelvic features to be a small Dinosaur allied to Scelidosaurus Owen. The 
ischia, however, are remarkably prolonged posteriorly, and find a parallel in Compsog- 
nathus Wagn. 

Believing them to be ischia, the inferior pelvic arches of Hadrosaurus were light and 
slender, the ischia parallel and light, and entirely incapable of supporting the weight of 
the animal, as was done by Megadactylus. The tail was no doubt the great support when 
the head was elevated. 

* The large pneumatic foramina in the vertebrae of this genus, together with those seen in the sacrum of Laelaps, 
explain the character of similar vertebras described as os quadratum of Iguanodon by ilautell and Owen, and sacrals 
of Hadrosaurus by Leidy. I regard the latter as indicative of a new genus allied to the Goniopoda. 

f Opportunity of reviewing this part of my essay having offered, I must point out the confirmatory evidence I 
have derived from Prof. Huxley's recent explanation of the structure of Hypsilophodon, with regard to my determin- 
ation of the pubes in Hadrosaurus. He proves conclusively its posterior direction, which view I adopt for Hadrosau- 
rus, contrary to my former supposition. 



The figure 29 is the result of the preceding considerations, but it is not to be consid- 
ered as completely demonstrated. They all go to show the narrow and prominent form 
of the abdominal region, which was associated with its posterior position, and the great 
lengths of the femora. Fig. a is a front view of the pubis ; b is an internal view of the 
ischium of Clepsysaurus. 

Dentition. — The teeth of this genus are very much smaller in relation to the size of 
the animal than in Iguanodon. They bear enamel on one surface only, the external for 
the inferior series as Leidy points out. Thus but one edge of the worn crowns is enam- 
elled, and acts functionally like that of the anterior faces of the incisors of Rodents.' They 
produce shear-like edges, cutting the vegetable food by a horizontal transverse motion. 


Proceed. A. N. Sci., Phil., 1868, 199. 

Trachodon mirabilis, Trans. Am. Phil. Soc, XI, 1860, 140. Tab. 

Upper Jurassic Bad Lands of Judith River, Nebraska. 

Known from teeth, and perhaps vertebrae and phalanges. 


Proc. Acad. Nat. Sci., Phil., 1858, 218, Cret. Kept. IT. S. 76, Tab. XII to XVII. 
Cretaceous green sand, New Jersey. 

There are eight localities in the green sand of Cretaceous age in New Jersey, from 
which I have seen portions of this species. 


Thespesius oecidenialis. Trans. Amer. Philoso. Soc, XI., I860, 151, tab. 
? Cretaceous Beds of Nebraska, between Moreau and Grand Rivers. 

Of this supposed species, Leidy says, "Had the remains of Thespesius and Trachodon been found in a deposit of 
the same age, I should have unhesitatingly referred them to the same animal, and I cannot avoid the suspicion that 
future investigation may determine them to be the same." In this he refers to Hadrosaurus mirabilis, which Hayden 
discovered in the Jurassic of Judith River, while the types of Thespesius were found by the same geologist, in a bed 
with other vertebrates, mostly reptiles, which he determined to be of Miocene age. 

Now, the extreme improbability of this type occurring in a Miocene bed will occur to many palaeontologists, as 
has to me. With the view of determining this point if possible, I instituted an examination of the forms brought by 
Dr. Hayden from this locality, and first of that most characteristic animal, the Ischyr other ium, of Leidy. This, as 
has appeared in the preceding pages, I believe to be a reptile, allied to Plesiosaurus, a conclusion which at once estab- 
lishes the Mesozic age of the bed. It coincides with the presence of Hadrosaurus, in indicating Cretaceous or upper 
Jurassic age. 


As Leidy has referred the eastern and western herbivorous Dinosouria to one on the same genus, and as there is 
much doubt as to whether the present animal is not one of them, I refer the latter here as an expression of the 
probabilities of the case. 


This herbivorous genus is, as remarked by its describer, an interesting representative of the Hylaeosaurus of the 
European Wealden. 


Tr. Am. Phil. Soc., 1860, 145. 

Upper Jurassic Bad Lands of Judith River, Nebraska. 

ASTRODOjST, Johnston. 
Amer. Journ. Dent. Sci., 1859. 


Cret. Kept. U. S., 10?, Tab. 

Cretaceous greensand, Maryland, (near Bladensburg. ) 

To a genus nearly allied to the present, should be referred the animal represented by 
a large tooth discovered by Thomas Wright in the Island of Wight, described and fig- 
ured by him in the Annals and Magazine Nat. History, 1852, p. 89. The creature has 
been of larger size than the Astrodon Johnstoni, and apparently of a formidable nature. 


Proceed. Ac. N. Sci., Phila., 1666, 317. 
Harpagmosauria Haeckel, 1866. 

Proximal tarsal bones distinct from tibia ; the latter closely embraced by the much 
enlarged astragalus, on its inferior and anterior faces, forming an immoveable articulation. 
Astragalus, with an extensive anterior articular condyle below, above in contact with the 
fibula, which is much reduced, especially distally. Anterior part of the ilium dilated, and 

This group is named from the abrupt flexure of the ankle in the middle of the 
tarsus, preventing the foot from being extended in line with the leg. 

It represents no doubt an early stage of developement of the Symphypoda, and is 
remarkably similar in the same points in the structure of the posterior extremity, to the 
embryo of the chick at about the ninth day. At that time the metatarsals of the bird are 
distinct, proximally joined by a single tarsal element, which itself is separated by the artic- 
ulation from a transverse piece composed of the confluent proximal tarsal series. The 
latter element is not at this time united with the tibia, but it is in contact with the fibula. 

and perhaps, 


The fibula in latter stages withdraws from this connection, and becomes much shortened 
and reduced.* 

The genera which belong to this order are, 

Laelaps, Cope ; 

Poecilopleurum, Deslongchamps ; 
Megalosaurus, Buckland ; 
Coelosaurus, Leidy; 

Bathygnathus, Leidy ; 
Aublysodon, Leidy. 

LAELArS, Cope. 

Proc. Acad. Nat. Sciences, 1866, p. 275; 1. c, p. 316; 1. c. 1867, p. 234. American Naturalist, 1867, 27. 
Dinodon, Leidy, Proc. A. N. Sci., 1868, 298, not Ibid., 1856, and Transac. Am. Phil. Soc, 1859. 

Loc. Cit. Leidy. 1. c. 1868. 

This species was described by the author from a number of bones and fragments derived from the top of tie 
"chocolate" stratum of Cook & Smock's upper bed of the Cretaceous Greensand of New Jersey, at a depth of 
about twenty feet below the surface. They were found by the workmen under direction of J. C. Voorhees, Superin- 
tendent of the West Jersey Marl Company's pits, about two miles south of Barnesboro, Gloucester co., N. J. The 
bones preserved were portions of the under jaw with teeth, portions of the scapular arch, including supposed pubes 
two humeri, left femur, tibia and fibula, with numerous phalanges, lumbar sacral and caudal vertebras, and numerous 
other elements in a fragmentary condition. 

The discovery of this animal filled a hiatus in the Cretaceous Fauna, revealing the carnivorous enemy of the 
great Herbivorous Hadrosaurus, as the Aublysodon was related to the Trachodon of the Nebraska beds, and the 
Megalosaurus to the Iguanodon of the European Wealden and Oolite. 

In size this creature equalled the Megalosaurus bucklandii, and with it and Aublysodon, constituted the most 
formidable type of rapacious terrestrial vertebrata of which we have any knowledge. In its dentition and huge 
prehensile claws it resembled Megalosaurus. The species is now rediscribed with additional observations and with 

t Zygomatic arch. — A portion 6.5 inches in length is j>erhaps the malar portion of the arch rather than the 
squamosal, since near the termination of its inner or concave face it is pierced by a large foramen, similar in position 
to the suborbital foramen. The bone is slender, chiefly strengthened by a strong external, horizontal ridge, which is 
probably the homologue of that noticed by Prof. Owen as dividing the face of the maxillary and malar in Scelido- 
saurus. Alone and below this rib, the bone rapidly thins away. There is little curvature, indicating a long slender 
zygoma perhaps as in Compsognathus. The foramen has not been closed above. 

Vertical depth inside of front of foramen, 18 

Horizontal depth zygoma, 15 

Maxillary bone. — A portion of the right maxillary displays parts of four alveolae: three of these have a flattened 
oval section, while the anterior is round, suggesting the presence of a canine-like tooth. One successional tooth in 
place extends from the bottom of the alveolus to within .75 inch of the maxillary border; it stands obliquely in place, 

*See Gegenbaur, 1. c. 


the posterior catting edge being directed outwards. The anterior alveolus is shallower than the second, and this 
shallower than the third, which gives an oblique slope to the fractured margin of the bone, and suggests the applica- 
tion of another skeletal piece. This I suppose to be the premaxillary, as the bone is externally too Hat to permit the 
median premaxillary suture to occupy that position. The upper portion may be related to the margin of the nares. 
A series of five foramina extends along the outer face of the bone opposite the middle of the depth of the alveola;. 
The alveola; are directed more anteriorly from behind forwards. 

Depth of alveolus, 34 

Length crown of successional tooth, 25 

Length piece embracing four alveola}, 01 

Mandible. — One portion from the anterior part of the ramus. The latter measure three inches in depth from the 
outer alveolar border, which is a little more elevated than the internal, and 1.5 in. in thickness at the fractured edge. 
A longitudinal series of vascular foramina extends along the middle of the external face. The teeth are implanted 
in deep alveola?, and had transversely oval compressed fangs; the sections of the crowns of teeth from different 
portions of the ramus differ. Two from the anterior region are considerably recurved, the concave or posterior edge 
deticulate to the base of the enamel, the anterior aspect minutely serrate, two fifths the length from the tip. Section 
at this point lenticular, lower down the anterior face becomes broader and rounded, giving a rounded cuneiform 
section. Throughout, one face is more convex than the other. A young posterior tooth yet in the alveolus (no. 3) 
is less recurved, subacute, and of more lenticular section, having both edges denticulate to the base of the enamel. 
Fangs hollow, the pulp cavity capacious but rapidly diminishing and short; the cast sulphide of iron and marl. 


No. 1; total length (fang broken), 2.33 

length of enamel, 1 . 83 

width below, .833 

anterior diameter, .438 

No. 2; length of crown (tip restored), 1.875 
anterior diameter, .5 

No. 3; length of crown, 2.125 
width at base, .688 

Larger teeth are indicated by fragments. The development of the teeth has apparently proceeded as in Megalo- 
saurus. The development of the dental papilla takes place within a niche of the alveolus, between it and the inner 
mandibular or maxillary wall. Small serate casps are found in this position beneath but a thin stratum of bone. In 
one situation a second successional tooth occupies a position between the primary cusp and the functional tooth, and 
is about intermediate in size between them. These successional teeth then increasing in size, by a horizontal move- 
ment, transverse to the cranial axis, place themselves close to the fangs of the functional teeth, into whose places 
they gradually rise. An absorption of the dental wall probably prepares the older tooth for shedding, at which time 
the apex of the successional tooth is ready for use.* 

Vertebra. — No cervical or dorsal vertebrae were preserved ; we have only as yet sacrals, and numerous caudals. 
All are much constricted medially, or hour-glass shaped, the centrum cylindrical in section throughout in most of the 
caudals, the anterior of the latter and the lumbars of deeper vertical than transverse diameter throughout. The 
articular surfaces are moderately shallow biconcave in all, most strongly in the subproximial caudals. The neural 
arches attached by permanent suture, and inferior surfaces for articulation of chevron bones. The caudals offer 
indication of neural spines ; their traces are on the majority low, and of considerable longitudinal extent. Articular 

*Deslongchamps figures a tooth as doubtfully belonging to Poecilopleuruni. It resembles that of a Crocodilian, and probably belongs to a species of thai 
subclass. He states that Megalosaurus-like teeth occur in the strata in which Poecilopleuruni was found. There is now much reason to believe that the latter 
are the true teeth of the genus in question. 



surfaces for chevron bones -were much narrowed anterior to the middle of series, so that we cau infer that the tail 
was proximally cylindrical. Zygapophyses turned upward, not outward. 

The portions of the three sacrals preserved indicate that the centrum is very much compressed, as in other Dino- 
sauria. The proximal caudals, or those with diapophyses, have also compressed centra, though this is less marked 
than in the sacrals. The diapophyses come off from the neural arch above its union with the centrum in four such 
vertebrae preserved. In these the arch is not eoossified. In the remaining nine there is no trace of diapophysis 
beyond a ridge visible in the anterior ones, and the arches are eoossified. In the four anterior there is on the poste- 
rior half of the median line below, a strong groove ; in the two median, a foramen penetrates the centrum ; in the 
posterior the groove is less posterior in its position. In the posterior series often it is represented by an indistinct 
plane. These vertebra; are relatively less compressed than the first, but have a more concave inferior outline. The 
neural spines of these have been apparently curved upwards and backwards, judging from the direction of the lines 
of ossific growth, as in Poecilopleurum. They originate a little anterior to the middle of the length of the vertebra. 
Anterior to this point the neural canal is only partially roofed over - , there being an opening into it just in front of the 
base of the neural arch. Anteriorly the roof would appear to be composed by the union of two horizontal lamina; of 
the anterior zygapophyses. The articular faces for chevron bones are small. 

Dimensions of an anterior caudal; length centrum, 

depth do. from suture of neural arch, 

width articular face (anterior), 
" centrum at middle, 
Length of median caudal. 
Breadth centrum, 
Length base neural spine, 
Length of a distal caudal (with neural canal). 
Diameter centrum transverse, 

" " vertical, 

Proximal caudal (with short diapophysis) length, 
Depth centrum, 
Width " 

Three separate vertebra; appear to be most probably sacrals, and indicate that this individual was not adult. 
Their form is much compressed, and the articular- surfaces are rather expanded and concave. The superficial 
layer of the latter is very thin, and covered with delicate raised stria;, mostly transverse in direction. They present 
the appearance of incomplete development, and would no doubt at a later period coossify with those of the adjacent 
vertebra;, forming the long sacrum common to the order. Their exterior dense walls are remarkably thin, and the 
internal structure of the centra is coarsely spongy or almost cavernous, being far less close and compact than that of 
the cancellous centra of the caudals. The largest of these has a strong median groove above, probably that of the 
neural canal: greatest elevation of articular surface 5 in. 2 lin., greatest width of same 4 in. 2 lin. The tissue of this 
centrum is so coarse as to resemble the borings of Teredo. In another a large foramen marks the mouth of a canal 
which enters the centrum just behind one of the articular surfaces, and above the thickest portion of the centrum . 
It descends obliquely towards the middle of the centrum, but its course can be traced only an inch. Foramen .9 inch 
in diameter. 

The number of caudals preserved is fourteen. From interruptions in the series I imagine that ten have been 
lost, probably a few more; I think the whole number can be estimated at twenty-five. Both distals and proximals 
are preserved; the former are small and slender, the latter compressed, similar to the sacrals, and with diapophysis, 
and neural arch not eoossified. 

This furnishes a remarkable contrast to Hadrosaurus, to which Leidy reckons fifty vertebrae, and a depth of 
tail of a foot and a half. 

*They thus resemble in several ways, the bone referred by Mantell and Owen to the place of the os quadratum, with doubt. There is little probability 
to ray mind, of this reference proving other than erroneous ; see the fig in PI. XI at the end of the volume. 




















Fig 30. 

In comparing this series with those of Poecilopleurum, 
so well illustrated by Desloiigchamps, it is observable that 
vertebra of similar proportions in the two are without diapo- 
physes in the former, while they possess them in the latter. 
Thus the diapophyses probably cease at a point in Laelaps 
anterior to the same in Poecilopleurum. It is also noticeable 
that while they are obliquely directed backwards in the latter, 
those having them as well developed in the former exhibit 
them transverse. 

Humerus. — Both are preserved, but lack the distal con- 
dyle; about half the coronoid fossa of one remains, furnish- 
ing an indication of the breadth of that extremity. They 
are proximally much dilated, having a very strong postero- 
external ala and a shorter antero-internal dilatation. They 
are not half the length of the femur; the shaft is flattened 
antero-internally. Of the proximal articulating surface a 
portion is lost, but a narrow surface continuous with it exter- 
nally does not extend further out on the dilatation than oppo- 
site to the middle of the shaft. I find no trace of a globular 
condyle, as is seen in Hadrosaurus. Coronoid fossa large and 
well marked, not near to penetrating; medullary cavity of shaft 
relatively smaller than in the bones of the leg. 

Length of humerus (restored), 
Greatest proximal breadth, 
Distal breadth across coronoid fossa, 
Circumference of shaft, 





These humeri are relatively shorter than in Hadrosaurus 
and Iguanodon, and the external alse do not pass so abruptly 
into the shaft as in them. They resemble most those of Poeci- 
lopleurum. They differ from these in being much dilated dis- 
tally, especially internally, and in having the coronoid fossa 
much more pronounced. 

l&re-ttmb. — In the lack of the necessary pieces, one can- 
not go far wrong in estimating the length after that of Poe- 
cilopleurum. In it the lower arm is three-fifths the humerus, 
which gives for Laelaps a length of 19.2 in. to the wrist. If 
we accept the Crocodile as the next nearest ally in the fore- 
limbs, we find the carpus and hand to be .75 of the humerus. 
The ungueal phalange preserved in Poecilopleurum is shorter 
than in the Crocodile; if however we add 9 inches to the 
length already estimated, we have for the whole 2 ft. 4 - 2 

This is, as will be hereafter shown, a little more than one 
fourth (1-3.71) the length of the hind limb. 


Left Femur. — The bead and summit of the great trochanter, and the posterior portions of the condyles, are broken 
away. The shaft is rather slender, and is strongly arched forwards and slightly outwards. The third trochanter is 
on the posterior face, is turned inwards, and marks one-third the length of the shaft from the supposed position of 
the head. Just below it the shaft is cyclo-trigonal, while for a short distance above the condyles it is flattened ante- 
roposteriorly. It is strongly concave between the condyloid ridges at the distal end. At this place the external face 
is convex, the internal concave as high as a point a little more than a fourth the total length. The concavity is sepa- 
rated from the anterior face by a strong ridge which is partly broken away. The anterior surface is turned posteriorly 
to the external condyle, while it is concave and turned forwards to the internal condyle. 

The posterior portions of the two condyles are broken away, so as to give their remaining portions almost exactly 
the form of the head of the femur in Hadrosaurus and Iguanodon. The dense layer of the remaining portions is 
much worn away, but enough remains to show that the external was rather the more prominent. The trochlear and 
popliteal concavities approach much nearer together than in Megalosaurus, causing a greater attenuation of the 
basis for the condyles. It cannot be ascertained whether the external condyle bore the small process behind seen in 

The neck is much compressed anteroposteriorly, and extends much interior to the line of the shaft. The poste- 
rior face is regularly convex, and then turns into the transversely convex exterior, which is divided above by the 
groove that separates the external trochanter. The broad posterior face narrows below this trochanter, and presents 
a strong convexity posteriorly, opposite the upper portion of the third trochanter. The outer trochanter has a flat 
anterior face, and presents a sharp margin inwards. It is separated from the neck by a deep longitudinal concavity. 
It is probably much shorter than the head of the femur, about as in Megalosaurus. 

Length of femur restored, 35.5 

" actual, 32. 

Transverse extent of condyles, 6.45 

Posterior breadth of neck, 6.5 

Anterior " of great trochanter, 3.25 

Diameter neck and " " 4.5 

" anterior groove between them (medially), 1.5 

Circumference shaft at middle, 11. 

This element, compared with that of Megalosaurus, differs in its considerably more slender form, and in its curva- 
ture. The femur of the latter genus is very stout, and has a straight axis. The posterior prolongations of the 
condyles are broken away, but if the external were as small as in Megalosaurus, it was more external, and the poplit- 
eal concavity not so abruptly distinguished from the posterior face of the shaft above. This extremity of the bone 
more nearly resembles that of the Poecilopleurum bucklandii, described and figured by Deslongchamps. 

In my original description (Proc. A. N. Sci., 1866) I reversed the position of this bone, I believe incorrectly, 
which has been observed by Leidj'. As it stands broken, the distal extremity is almost identical with that of Hadro- 
saurus, and the proximal with the trochanter furnishes a very good basis for condyles like tbose, of Megalosaurus; 
hence the error. 

The relative lengths of the femur and humerus of certain genera of this order may be compared as follows: — 

Iguanodon anglicus, 
Hadrosaurus foulkei, 
Laelaps aquilunguis, 
Poecilopleurum buekiandii, 

Left Tibia. — The tibia is more slender than that belonging to Megalosaurus described by Prof. Owen, and the 
distal articular surface, instead of being lozenge-shaped, is cuneiform, the inner wide extremity oval rounded. Inner 
transverse breadth of proximal head one fourth total length. Anterior crest very strong, much incurved, disappear- 
ing at between the proximal fifth and fourth of length; internal ridge on proximal half, strong, but not reaching 









22.5 in. 



12 in. 





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T Sinclair's Lith Flula. 

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5 as 

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Ev/olastee platyops Cope. 

T. Sinclair 1 

opjfa.: 8 Osteopjrqris cheZyclrinzis. J? JTucZarstes. 
oTirospTiys vnoZops. 

fcerfia r-?/ • %\j-t// ■ '/r//////>/ fir 

- -,;j- - 'mtamm 



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•:■ : 


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T.Sinclair lith.Philada 




39088 00625 6440