1919] Merriam: Tertiary Mammalian Faunas of Mohave Desert 461 



The Barstow Miocene tortoises seem clearly more advanced, than 

 the Oligocene Stylemys in specialization of the neurals and costals, 

 and to some extent in the development or stage of advance of the 

 epiplastral lip. 



The Barstow form seems in the nature of the epiplastral lip, m 

 form of the entoplastron, in width of the pectoral scutes, and in the 

 variations in width of the costals to be less specialized than some of 

 the forms of Testuelo. The stage of advance is approximately that of 

 Miocene forms like Testuelo pansa of the Pawnee Creek Middle Mio- 

 cene or T. impensa of the Madison River Upper Miocene. 



The Barstow form seems distinct from all of the described species. 

 In view of the fact that Testuelo vnelata and T. klettiana, described 

 by Cope from the Miocene of New Mexico, are from beds presumably 

 near in age to the Barstow beds the possibility of identity of the 

 species must be considered. T. klettiana is described as having a 

 quadrate pygial entirely unlike that of the Barstow species, while 

 T. unclata is a very large form. With the information available it is 

 not possible to refer the Barstow specimens to either of Cope 's species 

 from New Mexico. 



Measurements 



No. 21575 No. 21574 



Carapace, length along median line 232 mm. 



Carapace, greatest width ol96 317 



Plastron, greatest length 222 a375 



No. 21575 No. 21574 



A A, 





Length 



Width 



Length 



Width 



Nuchal bone 



33 mm. 



72 



72 



90 



Neural bone 1 



28 



18.2 



48 



39 



Neural bone 2 



24.5 



33 



40 



68 



Neural bone 3 



19.5 



32.2 



a43 



64.5 



Neural bone 4 



23.6 



40.2 







Neural bone 5 



16 



25.8 







Neural bone 6 



17.1 



31.5 







Neural bone 7 



25 



31.2 







Neural bone 8 



19 



014.4 







Anterior suprapygial bone 



19 



35 







Posterior suprapygial bone 



15.5 



25.5 







Nuchal scute 



al0.2 



29.8 



26.5 



18.2 



Vertebral scute 1 _ 



42.5 



o59 



83 



82.5 



Vertebral scute 2 



45 



62.5 



81 



nllO 



Vertebral scute 3 



50 



72 







Vertebral scute 4 



46.2 



57 







Vertebral scute 5 



45 









Pygial bone, length 24.5 



Pygial bone, width inner 36.5 



Pygial bone, width outer o23 



a, approximate. 



