4<o(> 



FOSSIL TURTLES OK NORTH AMERICA. 



the inguinal notch. Another peripheral is present which has the same texture and general 

 appearance as the other bones, but it possibly belongs to another turtle. II pertaining to this 

 skeleton it can be only the eleventh. 



516. 5i7- 5i8. 



Figs. 516-518. T estudo ligonia. Parts of carapace of type. X h. 



516. First peripheral and part of nuchal, nu. p, nuchal plate; nu. s, nuchal scute; per, I, first peripheral. 



517. Section of first peripheral near union with second. Upper surface toward the left. 



518. Ninth peripheral of type. 



The nuchal (fig. 510) had a length, in the median line, of about 100 mm.; a width, at the 

 free border, of 70 mm.; and a maximum width of 108 mm. The greatest thickness, at the 

 midline, is 21 mm. The portion occupied by the first vertebral scute stands at a distinct angle 

 with that in front of it. The first peripheral has a fore-and-aft extent of 81 mm., of which 75 

 mm. has been exposed on the upper surface. The thickness of the sutural border next the 



520. 



519- 522- 



Figs. 519-522. Testudo ligonia. Peripherals and epiplast of type. X$. 



519. Section of ninth peripheral, near union with eighth. 520. Supposed eleventh peripheral. 



521. Sectionof eleventh peripheral, near union with tenth. 522. Upper view of left epiplastron. 



second peripheral is 26 mm. The free borders of these bones are acute. Fig. 517 is a section 

 taken near the articulation with the second peripheral. 



The ninth peripheral (fig. 518) is high and narrow, the height being 92 mm., the width 

 along the free border 24 mm. There is no flare, and the free border is acute. The greatest 

 thickness, at a point 73 mm. above the free border, is 24 mm. Fig. 519 is a section taken near 

 the anterior sutural border. The free edge is acute. If the remaining peripheral (fig. 520) 



