386 PROCEEDINGS OF THE ACADEMY OF [May, 



to Terrapene Carolina or to a species closely related to it. It was 

 soon observed that Ihe ninth marginal comes into contact with the 

 last vertebral (fig. 6), a condition Avhich recalled Cope's Cistudo 

 eurypygia, and a close comparison proved that they are identical, one 

 of the portions of Ihe Port Kennedy specimen being fortunately 

 the right margin of the rear of the shell from near the midline to 

 the hinge. The question therefore arises whether or not the new 

 material confirms Cope's view of the distinctness of the species. 



The unusual width of the fourth and fifth vertebral scutes is 

 proved by Cope's type and confirmed by the Port Kennedy speci- 

 men. Belonging to the latter is a fragment of the carapace pre- 



senting a part of the nuchal, a part of the first and second costals 

 and the first and second peripherals (fig. 7). In T. Carolina the 

 fii'st vertebral does not usually encroach on the first peripheral 

 bone; in the fragment alluded to above the vertebral reaches over 

 on the first peripheral nearly to the sulcus between the first and 

 second marginals. The anterior vertebral must have been 34 mm. 

 wide, about 6 mm. wider than in a specimen of T. Carolina at 

 hand. We must conclude that the other vertebrals were wider 

 than they commonly are in T. Carolina. An estimate makes it 

 probable that the fourth vertebral in T. eimjpj/gia, type, was about 

 42 mm. wide. 



A comparison of the plastron of the Port Kennedy specimen 

 makes it evident that this portion of tlie t-hell was almost every- 

 where thicker than in the corresponding parts of the living species. 

 Nearly the whole of the border of the anterior lobe is thicker and 

 with a more rounded edge. The hypoplasti-on of T. Carolina at the 

 hinge is 3 mm. thick; that of T. eurypyc/ia, 4 mm. The thickness 

 of tlie sloping, scute-covered l>ordcr c.f the hinder lobe, at the June- 



