THORACOSAURUS. il 
vertebre of the Gavialis, or, as we may call it, Thoracosaurus macrorhynchus, 
appear also to have possessed the same discriminating character, as represented 
by Fig. 22, Plate 59, of the Atlas to Gervais’ Paléontologie. - 
Other fragments adherent to the mass consist of a portion of another cervical 
vertebra, a much mutilated posterior caudal vertebra corresponding in its proportions 
with the one above indicated, an uncharacteristic piece of an ulna, and a mutilated 
upper extremity of a humerus. 
A dermal plate and part of another, presented to the Academy by Dr. S. G. 
Morton, and obtained from the Green-sand of Mount Holly, Burlington Co., N. J., 
is probably referable to the same species. The specimens are black, dense, and 
heavy from the infiltration of ferruginous matters. They are deeply foveated on 
their free surface, and are devoid of any trace of a carina, The more perfect 
specimen, represented in Fig. 3, Plate I, is nearly oblong square, and measures 
three and a half by three inches in breadth, and is half an inch in thickness along 
the middle. Upon these dermal plates I formerly proposed the name of Thoraco- 
sdurus grandis." 
Since writing the preceding, I have received for examination a collection of 
crocodilian fossils from Prof. Cook, of Rutger’s College, New Brunswick, N. J., 
which are referable to the Thoracosaurus Neocesariensis. 'The fossils were obtained 
from the Green-sand of Monmouth County, N. J., and are black, dense, and in a 
good state of preservation. They consist of ten vertebra, and a fragment of a 
dermal plate resembling those above described, all apparently from the same indi- 
vidual, which had reached maturity. 
Of the vertebra, one, represented in Fig. 7, Plate III, appears to be the sixth 
cervical, and has lost its spinous and articular processes. It agrees in size and 
details with the specimen of a fourth or fifth cervical vertebra above described, and 
with that described by Prof. Owen as characteristic of the Crocodilus basifissus, 
excepting that its hypapophysis exhibits a mere trace of fission; a condition, how- 
ever, which indicates its more posterior position in the cervical series. 
Two other vertebre, preserved nearly entire, are the first and third dorsal, of 
which the latter is represented in Fig. 8, Plate III. The former has lost its hypa- 
pophysis, but otherwise both specimens resemble in the details of form the corre- 
sponding bones of the Mississippi Alligator. 
The remaining specimens consist of the series apparently unbroken, from the 
eighth dorsal to the second lumbar, inclusive. . The eighth and ninth dorsals, Fig. 
9, Plate III, have lost all the processes from their vertebral arches, and their bodies 
are coossified by a huge exostosis. The tenth dorsal, Fig. 10, retains its spinous 
process, and is five and three-quarter inches high posteriorly. The last pair of 
dorsals and the two lumbars, of which the first is represented in Fig. 11, have lost 
their vertebral arches. In form and proportions all the specimens agree with the 
corresponding bones of the Mississippi Alligator. 
Measurements of the specimens are as follows :— 
4 Proc, Acad. Nat. Sci. Phila. VI, 1852, 35. 
