240 



University of California . 



[VOU 3. 



the surface above which was covered with horny skin, the thick- 

 ness is 6 mm. The femoro-anal sulcus comes to the free edge 

 19 mm. behind the anterior end of the bone. 



Figure 3 presents a view of the first right peripheral both 

 from above and from the right-hand edge, which joined the 

 second peripheral. The left-hand border joined the nuchal. 

 The first peripheral resembles closely that of 0. guttata. It will 

 be observed that the outer anterior angle of the first vertebral 

 scute extends outward on the bone here described and comes 

 into contact with the second marginal scute. We have the same 

 arrangement here that we find in 0, leprosa, as shown by figure 

 30, page 102, of Boulenger's Catalogue of Chelonians. This 

 indicates that the first vertebral scute was broader than it is in 

 C. guttata. The peripheral mentioned above, probably the ninth 

 of the right side, resembles somewhat that represented by figure 

 4; but it is shorter autero-posteriorly and higher, the fore and 

 aft dimension being 15 mm., the height 19 mm. The longitu- 



surface and the anterior end of the bone. Accompanying 

 this bone there is the hinder outer angle of the hypoplastic >n, 

 extending from the suture with the xiphiplastron 

 ]l to the inguinal buttress. A view of a section 



this lot was derived from the Mascall beds and do not belong to 

 this species. 



From a comparison of the bones above described with the 

 corresponding pai-ts of C. guttata it appears that the carapace of 

 0. Jiesperia attained a length of five or six inches. Unfortu- 

 nately, I have not been able to compare the fossil species with 

 0. marmorata of the Pacific Coast. 



From the Rattlesnake beds, Rattlesnake Creek, Oregon. 



left ninth peripheral of an individual 

 somewhat larger than the one just 

 described. It is part of a lot num- 

 bered 552. Figure 4 shows the upper 



Figure 4. 



of the bone near the xiphiplastral surface is 

 shown in figure 5. It is of course possible that 



Figure 5. 



