TESTUDINID. 437 
MEASUREMENTS. 
Meter. 
Width, proximal notes 0.105 
Width, distal. . 110 
Length ..... . ; -110 
Thickness. ... : 109 
The free margin is slightly convex. 
To this description it may be added that the thickness of most parts of the bone is 20 mm. 
The free border is acute; most so near the midline. 
There is no satisfactory evidence that the bones which furnisht Cope’s figs. 4 and 5, of the 
plate cited in the synonymy, belonged to this species. 
The form of the pygal, the lateral borders of which are parallel, appears to distinguish this 
the Py8: nae y ; | PP iS 
species from all others of our fossil species of T estudo. 
Testudo niobrarensis Leidy. 
Figs. 575-578. 
Testudo (Stylemys) ntobrarensis, Letpy, Proc. Acad. Nat. Sct. Phila. 1858, p. 29; Extinct Mamm. 
Fauna Dak. and Neb., in Jour. Phila. Acad. Nat. Sci. Phila. (2), vit, 1869, p. 26. 
T estudo (Stylemys) niobrarensts, HAYDEN, Proc. Acad. Nat. Sci. Phila., 1858, p- 158. 
Stylemys niobrarensis, Cope, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 124.—Letpy, 2d (4th) Ann. 
Rept. U. S. Geol. Surv. Wyoming, 1871, p. 366; Contrib. Extinct Vert. Fauna West. Terrs., 1873, 
p. 225, plate iii, figs. 4-6.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 450. 
Testudo ntobrarensis, Lery, Contrib. Extinct Fauna West. Terrs., 1873, p. 340, plate xix, figs. 6, 8. 
This species was based on fragmentary bones which were collected by Dr. F. V. Hayden, 
in the year 1857, in what were regarded as Pliocene sands along the Niobrara River. These 
Fics. 575~578.—Testudo mobrarensis. Plastron, pygal, and suprapygal. U.S. N. M. 
577. Suprapygal and pygal. X 4. Seen from above. 
578. Section of pygal and suprapygal. 3%. 
575. Upper surface of plastron. 
576. Lower surface of plastron. > 
Geno eona 
deposits are now regarded as belonging to the Loup Fork Miocene. No exact statement 
regarding the locality 1s given, but it was in all probability within the state of Nebraska. The 
specimens are in the U. S. National Museum, at Washington. ; 
The materials described and figured by Leidy consisted of the anterior portion of the 
plastron, the posterior suprapygal and the pygal, the hinder median portion of the carapace, 
the distal part of one humerus, and the distal part of one femur. These did not all belong to 
one individual. The figures of the plastron, the pygal, and suprapygal, being parts most 
characteristic, are here reproduced. It seems best, considering the possibility that more than 
a single species is here included, to take as the type of the species the figured epiplastral lip. 
This is No. 956 of the U. S. National Museum. Leidy’s figure of the pygal and suprapygal is 
two-thirds the size of the original bones, altho he states in the explanation of the plate that it 1s 
the size of nature. 
