TESTUDINIDA;. 



403 



the right side have been thrust forward about 10 mm. in front of those on the left. Some por- 

 tions of neurals, costals, and peripherals are missing, especially on the right side, but all parts 

 are represented on one side or the other. The outer ends of the hyoplastra are wanting and 

 part of the outer end of the left hypoplastron. 



The species was a broad and rather deprest one, and in many respects it resembled the recent 

 Gopherus polyphemus. The following table presents some of the dimensions. When Cope's 

 measurements differ they are added in parentheses. 



Length of carapace 420 (408) 



Width of carapace 356 



Greatest length of plastron 440 



Length of anterior lobe 132 



Width of anterior lobe 200 



Greatest length of posterior lobe 1 20 



Width of base of posterior lobe 210 (200) 



The anterior border of the carapace (plate 67, fig. I; text-fig. 509) is truncate; the pos- 

 terior border between truncate and rounded. The free edge is everywhere acute. Where the 



509. 



FIGS. 509 AND 510. TestuJo lattcunea. Carapace and plastron of type. X } 

 509. Carapace. 510. Plastron. 



sulci between the marginal scutes cross the free border there is present a tooth or mucro. The 

 height of the bridge peripherals was about 85 mm.; while the extent of the corresponding 

 costals, transverse to the animal, was about 145 mm. The greatest thickness of the first periph- 

 eral is 1 8 mm. The nuchal bone occupies 62 mm. of the free border, and its greatest width is 

 95 mm. The hinder peripherals have a slight flare. The eighth has a height of 70 mm. and a 

 thickness of 22 mm. The pygal has a length of 34 mm. along the midline, a transverse extent 

 of 57 mm. at the upper border, and of 45 mm. along the free border. The first suprapygal is 

 bifurcate and comes into contact with the eleventh peripheral of each side, but not with the 

 pygal. The second pygal is broader than long. 



The neurals have not attained so high a degree of differentiation of form as they have in 

 most of the species of the genus. None of the series is octagonal. All are hexagonal, except 



