Hay: Description of New Species of Turtles. 



17 



found by a collecting party from the Museum in 1905, about two miles 

 north of Agate Springs quarry, in Sioux county, Nebraska. The de- 

 posits belong to the Lower Miocene. 

 The pygal and the eleventh periph- 

 eral are selected for description. 



The pygal (Figs. 6, 7) has an 

 extreme height of 112 mm. The 

 width of the upper border is 102 

 mm; that of the free border, 58 

 mm. The upper border is notched 

 for the supra-pygal. The thickness 

 of the border which articulated with 

 the eleventh peripheral is 30 mm. 

 The upper, or hinder, surface of the 

 bone is convex in all directions. 

 The free border is acute. 



The eleventh peripheral (Figs. 

 6, 8) is 45 mm. wide above; 87 

 mm. wide below. The height is 



98 mm. The outer surface is nearly plane next the pygal, strongly 

 concave next the tenth peripheral. The greatest thickness is 31 mm. 



FiG. 5. Inferiorview of shell of ley 

 tudo peragrans. \. 



Fig. 6. 



Fig. 7. 



Fig. 



Fig. 6. Upper side of pygal and eleventh peripheral of Testudoarenivaga. 



Fig. 7. Section along midline of pygal of Tesludo arenivaga. 



Fig. 8. Section of anterior end of eleventh peripheral of Testudo arenivaga. 



;;• 



