Loomis — Reptiles from the Titanothere Beds. 429 



The femur has a wide flattened head, the articulation extend- 

 ing around the whole end as in the modern forms. The tibia 

 very like that of a living C. palustris, as is also the astrag- 



1S 



ulus, which, 



however, has a shorter heel. 



8 



9 



For measurements see the figures, which are all to scale. 

 Chrysemys inornata, nov. spec. Figs. 10, 11. Xf. 



The genus Chrysemys, to which Hay* ascribes many of the 

 Eocene species described as Emys, has not been heretofore 

 found in the Oligocene, although to be expected in river 

 deposits. A good many small undeterminable fragments were 

 picked up through the summer ; and finally, while excavating 

 a titanotherium skeleton at the head of Bear Creek in Spring 

 Draw Basin — ten miles east of Creston Post Office, — directly 

 under the skull, as though crushed by the fall of that animal, 

 was discovered a complete carapace and plastron of C. inornata. 



The carapace is broadly oval and but moderately convex. 

 The anterior margin has a shallow median notch : the posterior 

 a distinct median notch, and. on either side three diminishing 

 scallops, one on each marginal plate. The nuchal plate is 

 much wider than long ; so that its lateral corners underlie the 

 first costal scute on either side. The antero-lateral borders of 

 vertebral plates numbers 1 to 6 are much shorter than the pos- 

 tero-lateral borders. The anterior sulcus of dorsal scute num- 

 ber 5 crosses the anterior end of neural plate No. 9. In general 

 appearance this species closely resembles Emys lativertebralis 

 Copef from the Wasatch : but on C. inornata the posterior 

 margin is scalloped (resembling C. scripta in this respect). 

 Then in E. lativertebralis the nuchal plate does not extend 

 under the first costal scute. Lastly, the tenth neural plate of G. 

 inornata is longer than that of E lativertebralis, while the 

 eighth is shorter. 



The plastron is about two-thirds the width of the carapace, 

 the meso-sternal plate being anterior to the pectero-humeral 

 suture. This plate is as wide as long and broadly rounded. 



*Bull. U. S. Geol. Surv., No. 179, p. 447. This Journal (4), xviii, 267, 

 1904. f Geog. Surv. West of 100 Meridian, vol. iv, p. 53. 



