Sinclair. 1 A New Tortoise . 247 



First marginal, length 44 



First marginal, width at costal margin 51 



First marginal, width at free margin (approximate) 67 



Third marginal, length 58 



Third marginal, width at costal margin 42 



Third marginal, width at free margin 51 



Sixth marginal, length 65 



Sixth marginal, width at costal margin 50 



Sixth marginal, width at free margin 50 



Eighth marginal, length 61 



Eighth marginal, width at costal margin 49 



Eighth marginal, width at free margin (approximate) 52 



Epi plastron, greatest width 151 



Entoplastron, anteroposterior diameter 81 



transverse : 88 



Hyoplastron, length along median suture 83 



The remains described belong' to a tortoise or land turtle 

 referable to Stylemys, a genus which is represented by large 

 forms in the White River and John Day beds. It is specifically 

 distinct from Stylemys neftrascensix and near Stylemys oregorwnsis 

 from the John Day. The name Stylemys calaverensis is proposed 

 for this new Californian species. 



The strongest points of difference between Stylemys nebras- 

 censis and the new form are found in the relation of the second 

 costal to the first two neural plates. A considerable amount of 

 individual variation is observable in this respect in the figured 

 specimens of Stylemys nebrascewxis. The second costal may be 

 in contact either with the second neural alone or with the second 

 and third neurals; the third costal, with the third and fourth 

 neurals, or with the second, third, and fourth. The Californian 

 species has the second costal in contact with the first two neurals. 

 The third costal may have a small contact with the missing 

 fourth neural, but this can not be definitely ascertained owing to 

 the worn condition of the bones. 



In addition to the specimen described, remains of tortoises 

 are known from several other localities in the Sierra Nevada region, 

 from gravels of the same age. Some fragments of marginal plates 



* Leidy, Smithsonian Contrib. to Knowledge. Vol. VI. "The Ancient Fauna 

 of Nebraska.'' PI, xix-xxiy, pp. 101-111. 



