176 FOSSIL TURTLES OF NORTH AMERICA. 
the interorbital space, whereas in 7. e/kader the same suture is equal to the whole width of the 
interorbital space. 
T. brachyrhina is a species with a blunter snout, a narrower lower jaw, and a much shorter 
symphysis. The skull is narrower behind in proportion to the length. 
T. procax also has a relatively narrower skull and the choane are placed further behind 
the snout. 
T. bauri, having been founded solely on portions of the shell, can not be compared with 
any species based on the skull alone. 
Toxochelys procax Hay. 
Figs. 224-228. 
Toxochelys procax, Hay, Bull. Amer. Mus. Nat. Hist., xx1, 1905, p. 181, figs. 13, 14. 
The type of the present species is a large, but somewhat damaged, skull which belongs to 
the American Museum of Natural History, New York. Its Siac is 234. It was obtained 
from Mr. H. T. Martin, who collected it in the Niobrara deposits along the Smoky Hill River, 
in Kansas, in 1gort. On the lower surface, the lateral wings of the pterygoids are broken away; 
also the hinder extremity of one maxilla, and a small portion of the palatines. On the upper 
surface, the greater part of the frontals and parietals is gone, as well as the whole of the jugals, 
Fics. 224-228.—Toxochelys procax. Skull and lower jaw. 3. 
224. Upper aspect of anterior portion of skull of type. 
25. Skull of type, showing palatal surface. 
26. Tip of lower jaw, with section (226a) along 
symphysis. No. 234A.M.N.H. 
7. Tip of lower jaw. No. 220A.M.N.H. 
8. Dentary bones. No. 2050 Kansas Univ. 
quadratojugals, and squamosals. On the lower jaw there are present a portion on each side 
of the symphysis and the hinder end of one dentary. 
The form of the skull (figs. 224, 225) is like that of T. latiremis, except that the outlines of 
the maxilla, as seen from below, are nearly straight, until the snout is approacht; whereas 
in T. latiremis the whole outline is convex. The skull is likewise more elongated than that of 
T.latiremis. The interorbital space is 27 mm. wide; and the pterygoids, where narrowest, are 
