DESCRIPTIONS OF FIVE SPECIES OF NORTH AMERICAN 

 FOSSIL TURTLES. FOUR OF WHICH ARE NEW. 



By Oliver P. Hay, 

 Of Washington, District of Columbia. 



Through the liberality of the authorities of the United State- 

 National Museum the writer has been permitted to study and describe 

 a number of specimens of fossil North American turtles. The results 

 of his investigations are here presented. 



GLYPTOPS PLICATULUS (Cope). 



In the collection of the U. S. National Museum are various speci- 

 mens of this species, most of them fragmentary. One of these is 

 of special interest, inasmuch as it displays distinctly the sulci bound- 

 ing the areas of the der- 

 mal scutes of the cara- 

 pace. This specimen is 

 Cat. No. 5458. and it was 

 collected by a member of 

 one of Prof. O. C Marsh's 

 parties at Como. Wyo- 

 ming, in 1884. Only 

 about the hinder half of 

 the carapace and a frag- 

 ment of one mesoplastron 

 are preserved. The parts 

 of the carapace are shown 

 in fig. 1. The neurals be- 

 gin with the third. On i 

 the right side the periph- 

 erals begin with the seventh: on the left, with the eighth. 



The peripherals of the hinder border curve slightly upward 

 toward the subacute free border. Those of the bridge region have 

 the free border uprolled somewhat, thus presenting a sort of gutter 



Proceedings U. S. National Museum, Vol. XXXV-No. 1640. 

 Proc. N. M. vol. xxxv— OS 11 161 



-POSTERIOB PORTION "I' CARAPACE 

 TOPS PLICATCLUS. 



>f Glyp- 



