456 



FOSSIL TURTLES OF NORTH AMERICA. 



15 mm. in width on the hinder lobe, and 30 mm. at the junction of hyoplastra and hypo- 

 plastra. The width on the entoplastron can not be determined, but it has caused the latter to 

 break along the midline. The gular sulci are not distinct, but they appear to have been broad, 

 and they extended on the entoplastron. The humero-pectoral sulcus starts, narrow and well 

 imprest, at the axillary notch, runs backward and inward nearly 75 mm., then turns sharply 

 and runs directly across the plastron, passing behind the entoplastron. The sulcus between 

 the pectorals and the abdominals is convex forwards. Laterally the pectorals have a width 

 of only 45 mm., but at the midline they are 75 mm. wide. The abdominals have a width of 

 175 mm. along the midline. The sulcus between these and the femorals is wide and deep, 

 and it runs directly across the plastron in front of the inguinal notches. The femorals extend 

 80 mm. along midline. The anal scutes meet along the midline for a distance of about 50 mm. 



The inner half of the lower surface of each hypoplastron is markt by longitudinal grooves. 



The remains of the carapace (figs. 611, 612, 613) of this species testify that it is a true 

 Testudo. One of the neurals (fig. 61 1) is octagonal, and the few costals present show that some 



610. 



1 



611. 



FIGS. 610 AND 6ll. TestuJo cam fester. No. 3930 A. M. N. H. 



610. Plastron. X|. Partly restored in front. 



611. Portion of anterior half of carapace. Xj. Most of nuchal and whole of first neural restored. 



were broad at the proximal end and narrow distally, while others were narrow proximally and 

 wide distally. 



The large octagonal neural is the second in the series. Its fore-and-aft diameter along the 

 midline is 67 mm.; its width across the middle of the length is 86 mm. The sides are concave, 

 the angles truncated. The third costal articulated with the right hinder angle of the second 

 neural. Its greatest width is 87 mm.; its distal width was about 50 mm.; its length about 

 240 mm. The second vertebral scute was about 160 mm. wide from side to side. 



There is present the upper end of another costal plate, probably the fourth on the right 

 side. The upper end is 48 mm. wide; the lower end of the fragment, perhaps a third of the 

 costal, is 75 mm. wide. 



The proximal portion of the right first costal is among the remains. Its proximal end is 

 100 mm. wide and most of this is concave and was in contact with the first neural. The latter 

 must therefore have had convex sides. On the outer half of the upper surface of the first costal, 

 are several deep, wide, and curved grooves, which mark the stages of growth of the scute 

 which covered it. Similar grooves are found on other costals. The costals are about 13 mm. 

 in thickness. 



