122 FOSSIL TURTLES OF NORTH AMERICA. 



\\ hilt- related to T . strenuus, this species shows several differences. So far as the sculpture 

 of the costals can he compared, that of T. rtrenuus consisted of more numerous and deeper 

 grooves. The entoplastron of T. strenuus was much larger than that of the species here 

 descrihed. As shown hv the section taken at the junction with the hvpoplastron the xiphi- 

 plastron of T . strenuus thickened much more rapidly and from a less acute edge, and its 

 hinder portion was considerably thicker than in T . dares. 



In the collection of the Geological Survey of Georgia, at Atlanta, are some portions of a 

 turtle which appears to belong to this species. Indeed, there are reasons for believing that they 

 are portions of the same individual as the type bones. They are believed to have been secured 

 in the same locality and formation as the carapace of Pcritresius ornatus; that is, on Bonna- 

 hachee Creek, Stewart County, Georgia, in the Ripley formation, of the Upper Cretaceous. 



Among the fragments is one including apparently the anterior inner angle of the hypo- 

 plastron. Sixty mm. behind the supposed hyohypoplastral suture the thickness is 26 mm. 

 Toward the suture mentioned the thickness is reduced. Here the upper two-thirds of the bone 

 is beveled off, showing that the hyoplastron somewhat overlapt the hvpoplastron. 



Another plastral fragment belongs probably to the hvpoplastron behind the inguinal notch. 

 Toward the median longitudinal suture the thickness is 16 mm. Toward the free border the 

 thickness is much reduced, but the edge is rounded. The xiphiplastral bone in the American 

 Museum shows that as the free border was continued backward it became acute. 



Another bone appears to be the second peripheral. It is ioo mm. long on the subacute 

 free border. The height was originally at least 82 mm. and the greatest thickness is 25 mm. 

 The upper surface is convex from end to end, nearly plane up and down. 



Named after Dares, a pugilist beaten in an encounter described in the /Eneid, book v. 



Taphrosphys nodosus Cope. 



T/iphrrjspliys nodosus, Cope, Ext. Batrach., Reptilia, Aves N. A., 1870, pp. 159, 167, plate i, fig. 16; Vert. 

 Cret. Form. West, 1875, p. 264. Hay, Bibliog. and Cat. Foss. Vert. N. A., 1 002, p. 4^8. 



The type of the present species forms No. 1480 of the American Museum of Natural 

 History. The remains are evidently those of a large, thin-shelled turtle; but these remains 

 are meager and fragmentary. They were obtained at Hornerstown, Monmouth Count}-, New 

 Jersey, apparently from the uppermost bed of Cretaceous greensand. The fragments are 

 charged with iron pyrites and are disposed to fall to pieces. Portions of costals are to be 

 recognized and a peripheral or two. 



Cope figured portions of 2 costals. His fig. 16 is from a fragment 58 mm. wide and 10 mm. 

 thick, but the inferior layer of the bone has peeled off. Another bone which comes down to an 

 acute edge is probably a peripheral. Its thickness at a distance of 25 mm. from the edge is 

 q mm.; still farther away, it becomes 12 mm. Another piece of bone is part of a bridge 

 peripheral, having two sculptured faces at about a right angle with each other. 



The sculpture will, more than anything else, assist in the recognition of the species. This 

 consists of pits and grooves, the latter anastamosing more or less and separating tortuous 

 ridges and pustules. The general effect is that seen on the carapace of a coarsely sculptured 

 ti lonychid. About 4 ridges are crost by a line 20 mm. long. 



This species will perhaps eventually be found to belong to a genus distinct from Taph- 

 rosphys. Indeed, the present writer knows of no characters distinguishing it from Peritresius 

 ornatus (Leidy). 



Genus AMBLYPEZA nov. 



A genus of pleurodirid turtles which differs from Taphrosphys in having the nuchal bone 

 shorter and its front relatively broader and in having the free borders of the hinder peripherals 

 thick and obtuse. Apparently a nuchal scute was present. 



Type: Amblypeza entellus Hay. 



Amblypeza entellus sp. nov. 

 Figs. 125-132. 



I he type of this species is a lot of bones which belong to the collection of the Geological 

 Survey of New Jersey, and which were loaned to the writer by the present State geologist. Dr. 



