Case.] Turtles. 371 



TOXOCHELYS. 



Toxochelys Cope, Proc. Phil. Acad. Nat. Sci., 1873, p. 10. 



Toxoclielys latiremis. 



Torochelys latiremis Cope, Proc. Phil. Acad. Nat. Sci., 1873, p. 10; Ciet. 

 Vert., p. 98, pi. vin, ff. 1-2; Proc. Amer. Phil. Soc, 1877, p. 176. 



The skull of this species is the best known part of the skele- 

 ton. The maxillaries are broad posteriorly, with the alveolar 

 surface slightly concave from side to side. Near the posterior 

 end the cutting edge of the maxilla is scarcely developed, but 

 begins about a centimeter from the end and rises rapidly until 

 in the middle and anterior portions of the bone it is deep and 

 strong. The base of this edge is marked internally by several 

 deep pits. The posterior end of the bone shows a broad articu- 

 lar face for the jugal. The middle part of the internal edge 

 joins the palatine, and, anteriorly, it unites with the vomer and 

 premaxillary. The posterior part of the upper edge is rounded 

 to form the lower portion of the orbit. 



The premaxillaries are longer than broad, with a deep cutting 

 edge. At the base of this edge, the lower surface of the pre- 

 maxillaries are excavated, forming a rather deep pit on the 

 median line perforated by a foramen. Externally, the surfaces 

 of the premaxillaries are rugose and pitted. They form the 

 lower surface of* the anterior nares, the edge of the jaw formed 

 by the maxillaries and premaxillary being the lowest part of 

 the arc. 



The prefrontals are strong and thick. They are united on 

 the median line for the anterior two -thirds of their length, and 

 rapidly separate to inclose the anterior ends of the frontals. 

 United with the ascending process of the maxillaries, they form 

 the upper and lateral edges of the anterior nares, which are 

 completed by the premaxillaries below. The nares are large 

 and a little broader than high. Posteriorly the outer edge of 

 the prefrontals form the anterior portion of the upper border of 

 the orbit. The frontals narrow anteriorly, to be inserted be- 

 tween the prefrontals, and far forward beneath them, appear- 

 ing much further forward on the inferior than on the superior 



