trNDETERMINED CROCODILES. I7 



Delaware, presented to the Academy by T. A. Conrad, is represented in Fig. 7, 

 Plate II. It belonged to a young animal, and has lost its arch at the sutural con- 

 junction. It measures fifteen lines long, and is provided with very robust para- 

 pophyses. The hypapophysis is AveU developed and associates the latter processes, 

 forming together a large crescentoid ridge, deeply notched at the middle. It proba- 

 bly belongs to the same species as the vertebrae above described from Timber Creek. 

 The museum of the Academy contains a fragment of a left dental bone with a 

 tooth, of a small Crocodile, or of a young individual of a large one, presented by 

 C. C. Abbott. It was found in Monmouth County, N. J., and is represented in 

 Figs. 22, 23, Plate IV. The specimen resembles in form the corresponding portion 

 of the lower jaw of Harlan's Crocodile, of which it may be part of a quite young 

 individual. The suture for the splenial bone, however, does not reach the symphysis 

 as in the fragment characteristic of Bottosaurus Harlani — ceasing about one inch 

 short of it. Besides three alveoli, there are preserved portions of five others, and 

 the third behind the symphysis still retains a tooth. The latter has a compressed, 

 conical crown, with its inner and outer surfaces defined by a prominent carina-like 

 ridge. The surfaces are finely rugose longitudinally, and the carinse are rugose in 

 a divergent manner. The crown measures five lines in length and width, and a 

 line less from without inwardly. 



Another specimen belonging to the cabinet of the Academy, represented in Fio-. 

 8, Plate II, is a fragment of a small Gavial skull from the Green-sand of Burlington 

 County, N. J. In construction it bears a resemblance to the corresponding part of 

 the Vincenttown skull, to which I by no means feel sure it does not belong, thouo-h 

 it differs in some important points. The forehead, in the fragment, between the 

 position of the post-frontals is quite flat, while it is decidedly concave in the 

 Vincenttown skull. The frontal is less prolonged to meet the parietal than in the 

 latter. The dividing ridge formed by the parietal between the temporal fosste is 

 even slightly greater than in the Vincenttown skull, while the distance between the 

 orbits at the anterior broken end of the specimen is only two inches. The upper 

 surface of the parietal and frontal is also more strikingly foveated than in the 

 Vincenttown skull. 



Four specimens of teeth, from Blackwoodtown, Camden County, N. J., pre- 

 sented to the Academy by Dr. J. L. Burtt, may probably belong to the same species 

 as the fragment of skull just described. The more perfect are represented in Figs. 

 7, 8, 9, Plate I. They have the form, curvature, and proportions of the teeth of 

 the living Oavialis Gangetieus, and are proportionately narrower than those of 

 Thoracosaurus Neocesariensis, and are also more finely striated. 



Figs. 22, 23, Plate III, represent the mutilated crowns of two teeth of a croco- 

 dilian reptile, supposed to have been obtained from a Green-sand deposit of North 

 Carolina, submitted to my examination by Dr. Isaac Lea. One of the specimens. 

 Fig. 22, is straight and conical, circular in transverse section, with an acute ridge 

 in front and behind which defines the inner and outer surfaces. The latter at base 

 are smooth, and apparently have been so at the apex, which is too much broken to 

 determine the fact positively. The intermediate portion of the surfaces is nearly 

 regularly fluted ; the ridges separating the concave grooves extending from the 



3 March, 1865. 



