PLATE XVII. 



Figs. 1,'i. — liaeiiaarenosa heidy. Plastron iind carapace. Page 148. 



Figs. ■iS.—llaeiia jmiiderom Cope. Carapace, three-fifths natural size: :!, part of margin; 3a, from 



within. Page lot). 

 Fig. 4. — Marginal bone ; a, its edge. 



Fig. 5. — Anterior marginals; a, sutural edge of posterior. 

 Fig. 6. — Ingiiinal or asillnry marginal. 



Fig. 7. — Common suture of two costals and a marginal at septum. 

 Fig. 9. — Distal end of a costal. 



Figs. 9-13.— £'mi/« seplariim Cope. One-fourth natural size ; 9, plastron from above. Page 139. 

 Fig. 10. — Anterior part of margin of carapace, with part of internal septum. 

 Fig. 11. — Internal septum of one end of carapace. 

 Fig. 12. — Portion of carapace, with vertebral scutum. 

 Fig. 13. — Costal bones of carapace. 



