298 FOSSIL TURTLES OF NORTH AMERICA. 



still less developt than in Chrysemys. The dentary bone of E. wyomingensis (figs. 398, 399) 

 agrees well with the maxilla of this skull. 



Text-figs. 367-374 represent various parts of the skeleton of the same individual. 



It is evident that this genus began its existence at least as far back as the Wasatch. An 

 examination of Cope's Emys lativertebralis (Wheeler's Surv. 100 Merid., iv, part ii, plate 

 xxviii, figs. 1, 2) shows that it possest strongly developt inguinal buttresses, which articulated 

 with the visceral surfaces of the fifth and sixth costals. The genus continued apparently until 

 the middle of the Uinta, as evidenct by the presence there of E. callopyge and E. uintensis. 



We are unable to determine as yet the relationships of this genus to Kachuga, Callagur, 

 Batagur, and Hardella, of Asia. It seems possible that some species of Echmatemys made its 

 way to that continent from America and thru a modification of its jaws gave origin to these 

 genera. 



Key to the Described Species of Echmatemys. 



A 1 . Wasatch and Green River species. 

 a 1 . No dorsal keel. 



1. Neurals broader than long; gulo-humeral sulcus crossing behind entoplastron; 



gular scutes reaching entoplastron lativertebralis 



2. Neurals unknown; gular scutes not reaching the entoplastron; gulo-humeral 



sulcus crossing on entoplastron cibollensis 



3. Sulci of carapace deeply imprest; costals swollen just outside of costo-vertebral 



sulci; bones thick and heavy testudinea 



4. Bones rather thin; beveled surface on upper side of hinder plastral lobe narrow. . euthneta 

 a 2 . A dorsal keel; bones of carapace deeply imprest by sulci; bones thin megaulax 



A 2 . Bridger species. 



a 1 . Inguinal buttresses not extending half-way from free border of hinder lobe to midline. 



1. Vertebral scutes and neural bones considerably longer than wide wyomingensis 



2. Vertebral scutes and neural bones wider than long pusilla 



a . Inguinal buttresses reaching half-way from free border of hinder lobe to midline. 



b l . Third vertebral scute about seven-tenths its length. 



1. Fourth neural octagonal haydeni 



b 2 . Third vertebral about eight-tenths its length. 



2. Third vertebral about 0.78 its length; anterior lobe not expanded. . . . stevensoniana 



3. Third vertebral 0.80 its length; anterior lobe of plastron expanding in front 



of axillae septaria 



4. Third vertebral about 0.81 its length; epiplastral lip contracted, tootht. . . . arethusa 



5. Third vertebral 0.82 its length; axillary buttress rising high; marginal scutes 



not high on anterior peripherals cyane 



6. Third vertebral 0.82; humero-pectoral sulcus crossing behind entoplastron; 



free borders of shell in front obtuse shaughnessiana 



b 3 . Third vertebral about nine-tenths its length or more. 



7. Third vertebral 0.87 its length; second vertebral still wider; anterior mar- 



ginals rising high on peripherals ocyrrho'e 



8. Third vertebral 0.97 its length and urn-shaped; sulci not in deep valleys; 



axillary scutes not reaching the fifth marginal trgle 



9. Third vertebral as wide as long; the sulci of carapace in deep valleys; 



axillary scutes broadly joining fifth marginals naomi 



a . Little known species; said to have a very wide epiplastral lip and a deeply notcht 



plastron latilabiata 



A 3 . Uinta species. 



a 1 . Vertebral scutes urn-shaped, the first narrower than the others callopyge 



a. 2 Vertebrals with straight sides; the front the widest uintensis 



Echmatemys lativertebralis (Cope). 

 Text-figs. 375-378. 



Emys latdabiatus, Cope, Syst. Cat., etc., Report to Engineer Dept. U.S. Army, 1875, p. 36; Ann. Report 

 Chief Engineers, 1875, App. LL, p. 1016, of reprint, p. 96. Not E. latilabiatus of 1872. 



Emys lativertebralis Cope, 1877, Wheeler's Surv. West 100th Merid., iv, part ii, p. 53, plate xxvii, figs. 

 1-3; plate xxviii, figs. 1, 2; Amer. Naturalist, xvi, 1882, p. 991, fig. 10; Vert. Tert. Form. West, 

 1884, p. 129. Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 448. 



