364 FOSSIL TURTLES OF NORTH AMERICA. 



exact age of the deposits is not known, but they belong probably either to the late Pliocene 

 or to the Pleistocene. 



The individual was of larger size than any belonging to any existing species. The right 

 fourth peripheral (fig. 463) has a length of 26 mm., from which we may infer that the carapace 

 had a length of about 220 mm. The anterior end of this peripheral has a thickness of 8 mm.; 

 the hinder end a thickness of 19 mm. On the outer surface is a sharp longitudinal keel, which 

 ran from the free border of the anterior peripherals to that of the posterior peripherals. This 

 keel borders outwardly a broad gutter-like groove. Fig. 464 shows the region of the seventh and 

 eighth marginal scutes, with a section across the seventh. Portions of the second and third cos- 

 tal scutes are presented. The thickness of the costals varies from 4 mm. to 6 mm. A frag- 

 ment of the dorsal region shows that the midline of the carapace was concave transversely. 



The lateral hinge-line appears to have had a length of about 70 mm. Its thickness is 10 

 mm. The entoplastron (fig. 465) is subcircular in outline. It varies in thickness from 5 mm. 

 to 7 mm. The border of the hinder lobe, at the hypoxiphiplastral suture, is 13.5 mm. 



Terrapene eurypygia (Cope). 

 Figs. 466-4-0. 



CistuJo eurypygia, COPE, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 124. 



Terrapene eurypygia, HAY, Proc. Acad. Nat. Sci. Phila. 1902, p. 385, figs. 6, 7; Bibliog. and Cat. Foss 

 Vert. N. A., 1902, p. 449; Maryland Geol. Surv., Pliocene and Pleistocene, 1896, p. 169, pi. xi, fig. 2. 



The present species has as its type a fragment of the hinder portion of the carapace which 

 was discovered by Dr. Samuel Harrison, on Oxford Neck, Talbot County, Maryland, in 

 Pleistocene deposits, associated with remains of Elephas primigenius, Cervus canadensis, 

 Odocoileus virginianus, and Chelydra serpentina. This type is now in the American Museum 

 at New York and bears the catalog number 1484. It is here represented by fig. 466. 



Cope's type presents a portion of the right seventh costal plate, portions of the costals of the 

 eighth pair, the suprapygal, the pygal, and the tenth and eleventh peripherals. Those charac- 

 ters which in this type appear to distinguish the species from T. Carolina are the greater breadth 

 of the fifth vertebral scute and the union of this vertebral with the tenth marginal scute. It is 

 proper to remark here that the present writer, in his description of this species in the Pro- 

 ceedings of the Philadelphia Academy, called the tenth marginal the ninth. 



An estimate makes it probable that the individual to which the type fragment belonged 

 had a length of carapace equal to about 140 mm. The fifth vertebral scute had a width of 40 

 mm. The width of this vertebral in T. Carolina is variable, but out of 6 individuals observed, 

 only I, with shell 130 mm. long, had this scute as much as 39 mm. wide. In T. eurypygia 

 the fifth vertebral joins the tenth marginal scute by a sulcus 4.5 mm. long. Usually in T. 

 Carolina these two scutes fail to reach each other by some millimeters. As stated by the author 

 elsewhere, an examination of eighteen specimens of T. Carolina showed that in only one the 

 fifth vertebral was in contact with the tenth marginal on both sides, while in another these 

 scutes were in contact on only one side of the carapace. Relying on the type alone we might 

 conclude that possibly T '. eurypygia is only an individual variation of T '. Carolina. 



In 1899 (Jour. Phila. Acad., XI, pp. 193-267) Professor Cope described various remains 

 of the vertebrates which had been collected by Messrs. Dixon and Mercer in the Port Kennedy 

 cave. Among other things there were three tortoises found, viz. : Clemmys insculpta, C. per- 

 crassa, and Toxaspis (Terrapene} anguillulata. There belonged to the collection, however, 

 another box-tortoise which was not mentioned by Cope, and was perhaps not seen by him. 

 These remains consist of almost the whole of the plastron and of various fragments of the 

 carapace and the right humerus. 



An examination of these bones showed that they belonged either to Terrapene Carolina or 

 to a species closely related to it. It was soon observed that the tenth, or antepenultimate, 

 marginal scute comes into contact with the last vertebral (fig. 4670), a condition which recalled 

 Cope's Cistudo eurypygia, and a close comparison proved that they are identical, one of the 

 portions of the 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. 



