FOSSIL TURTLES OF NORTH AMERICA. 



made apparently for Dr. Baur, and here reproduced (fig. 18), represents the first as small and 

 occupying the space between the costals of the eighth pair. The suprapygal of No. 336 is 

 large. Its length is 36 mm., its width anteriorly 14 mm.; the maximum 64 mm.; the posterior 

 width 38 mm. This bone somewhat resembles in form that of a Testudo. 



The costal plates narrow in succession backward. The peripherals are 1 1 in number on 

 each side. Anteriorly and posteriorly they are high; over the bridges they are low. The 

 first and second have a height of 35 mm.; the fifth, 18 mm.; the ninth, 40 mm. 



Figs. 19-27. Glyptops plicatulus. No. 336 A. M. N. H. 



X Somewhat crusht 



19. Plastron. Xj- Shows bones and many of the 



scute areas. 



20. Scapula. X. Procoracoid process, on the 



right, shortened by crushing. 



21. Coracoid and procoracoid process of scap- 



ula. X. 



22. Right humerus. Xjf- Dorsal surface. 



23. Pelvis from below. 



fore and aft. 



24. Pelvis from left side. X. 



25. Right femur. X From tibial border. 



26. Right femur. X From dorsal surf ace ; some- 



what crusht. 



27. Digital bones. XL 



The plastron is flat (fig. 19). Its length is 260 mm. The anterior lobe is 80 mm. long; 

 its width at the base, 122 mm. The edges are thick and rounded. The bones at the epihyo- 

 plastral suture are 8 mm. thick. The entoplastron is 43 mm. long and 47 mm. wide and 

 broadly rounded behind. The hyoplastrals meet at the midline about 50 mm. The meso- 

 plastra differ in width at the midline, the left being 30 mm. wide, the right 22 mm. The 

 hinder lobe is 78 mm. long and 106 mm. wide at the base. The hinder border is truncated. 

 The free borders are acute-edged. The bone thickens rapidly from the borders to about 10 mm. 



The plastral bones are joined to the bridge peripherals by the usual rough sutures. Strong 

 buttresses rise to the costals. 



The sulci bounding the epidermal scutes are extremely obscure and in many places can 

 not be determined. Where they can be observed they have been represented in the diagram- 

 matic figures. Those of the plastron are less difficult of observation. The gular scutes are 

 very broad, the sulci bounding them posteriorly curving outward and backward to near the 

 epihyoplastral suture. The intergulars can not be made out on No. 336, but they are shown 

 by Baur in a figure furnisht for him by the United States Geological Survey (plate 5, fig. 5). 



