TESTUDINID^:. 



437 



MEASUREMENTS. 



Meter. 



Width, proximal 0.105 



Width, distal no 



Length 1 1 o 



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 

 species from all others of our fossil species of Testudo. 



Testudo niobrarensis Leidy. 



F 'g s - 575-578- 

 Testudo (Stylemys) niobrarensis, LEIDY, Proc. Acad. Nat. Sci. Phila. 1858, p. 29; Extinct Mamm. 



Fauna Dak. and Neb., in Jour. Phila. Acad. Nat. Sci. Phila. (2), VH, 1869, p. 26. 

 Testudo (Stylemys) niobrarensis, HAYDEN, Proc. Acad. Nat. Sci. Phila., 1858, p. 158. 

 Stylemys niobrarensis, COPE, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 124. LEIDY, 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 niobrarensis, LEIDY, 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 



577- 



578. 



FIGS. 575-578. Testudo niobrarensis. Plastron, pygal, and suprapygal. U. S. N. M. 



575. Upper surface of plastron. X. 



576. Lower surface of plastron. X. 



577. Suprapygal and pygal. Xj. Seen from above. 



578. Section of pygal and suprapygal. Xi- 



deposits are now regarded as belonging to the Loup Fork Miocene. No exact statement 

 regarding the locality is 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 is 

 the size of nature. 



