39 6 



FOSSIL TURTLES OF NORTH AMERICA. 



costal scutes of S. conspecta lies well in front of the hinder border of the peripheral bones. The 

 carinae along the sides of the Oregon species are usually more distinct than in the White River 

 form, in which they seem never to be well developt. 



Styhmys conspecta belongs to a later epoch than does S. nebrascensis and has evidently 

 advanct to a stage nearer to Testudo than the earlier species. 



From S. capax the present species differs in being of a more elongated form and in having 

 the free borders of the peripherals very acute instead of obtuse. 



Stylemys calaverensis Sinclair. 



Teit-figs. 501, 503. 

 Stylemys calaverensis, SINCLAIR, Univ. of Cal. Pubs.; Bull. Dep't. of Geol., HI, 1903, p. 243, figs. I, 2. 



This species is represented by little else than the type, which belongs to the University of 

 California. It was found in the auriferous gravels about 2 miles below Vallecito, Calaveras 

 County, California. These gravels have been supposed to belong in the Miocene. It has not 

 been seen by the writer, and the following description is based wholly on Sinclair's description 

 and illustrations. 



The specimen consists of the crusht anterior two-thirds of the carapace and plastron. 

 The carapace (text-fig. 502) includes the greater portion of the first 6 costals of the left side, 

 the proximal ends of the second, third, fourth, and fifth costals of the right side, the second 



502. 503. 



FIGS. 502 AND 503. Stylemys calaverensis. Carapace and plastron of type. X e- 



502. Carapace, c.p. l,c.f>. 2, first and second costal bones; n.l,n.2, 



neurals; m. s. 3, m. s. 4, third and fourth marginal scutes. 



503. Portion of plastron. 



and third neurals, and a portion of the first. The plastron is represented from the front to 

 near the hinder border of the hypoplastron. 



In the crushing that has affected the shell there has occurred a slipping of parts near the 

 midline. The first costal of the left side overlaps a portion of the first neural. The second and 

 third neurals retain their original relations with the second and third costals of the right side, 

 but overlap the proximal ends of those of the left side. The three next costals of the left side 

 overlap and hide the corresponding neurals. Hence, only the second and third neurals and 

 a portion of the first are to be seen. 



H|| An estimate based on Sinclair's description and illustrations and the assumption that the 

 proportions of the species are about as they are m Stylemys nebrascensis shows that the carapace 

 had a length of about 405 mm. and a width of about 400 mm., being thus nearly as broad as 

 long. The bridge peripherals of the left side show distinctly in Sinclair's figure, here repro- 

 duced, but this is probably due to the crushing of the specimen toward the right side. On the 

 other hand the peripherals in front of these show hardly as much of their width as might be 



