246 FOSSIL TURTLES OK NORTH AMERICA. 



Adocus agilis Cope. 

 Plate 36, fig. 3. 



Adocus agilis, COPE, Proc. Acad. Nat. Sci. Phila. 1868, p. 235; Cook's Geol. New Jersey, 1868 (1869), 

 p. 734; Ext. Batrach., Reptilia, Aves N. A., 1869, pp. ii, 233, 234; Proc. Amer. Philos. Soc., 

 xi, 1870, pp. 296, 297, 549; Op. cit., xn, 1871, p. 44; Vert. Cret. Form. West, 1875, p. 262. HAY, 

 Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 444. 



The type of this species is in the American Museum of Natural History and bears the 

 number 1135. It was collected in the upper bed of the Cretaceous greensand of New Jersey, 

 at Barnesboro. 



The only portion of the animal represented is the plastron (plate 36, fig. 3) and this is not 

 complete. Cope states in his description that the extremities of both lobes are broken off; but 

 at present the hinder lobe is complete on the right side. The front of the anterior lobe being 

 gone, the total length of the plastron can not be determined with exactness. Cope estimated it 

 at 450 mm.; but this is certainly an error; it was probably not greater than 400 mm., and 

 more probably about 390 mm. 



The plastron is short and broad, but yields in these respects to that of//, punctatus. The 

 dimensions may be obtained from the table on page 242. The plastron is very flat, even out to 

 the suture with the peripherals of the bridge, but it is possible that the bridge has been distorted 

 through pressure. The entoplastron has its anterior angle now broken off, but Cope gave its 

 length as 69.5 mm. Its width is 91 mm. The free edge of the hyoplastron, just in front of the 

 axillary notch, is rounded in section. The bridge is, relatively to the length of the plastron 

 behind the entoplastron, longer than in any species with which it is compared on page 242. 



From the inguinal notch the free borders of the hinder lobe curve gradually to the midline 

 behind. These borders are acute, and from them the bone thickens rather rapidly and without 

 the intervention of a groove on the upper surface. The center of the lobe has no depression 

 such as we find in A. lacer and to a less extent in A. beatus. On the hinder half of the upper 

 surface of each xiphiplastron there is a large curved depression which marks the place of 

 articulation of the pubis. It is not so deeply imprest as it is in A . lacer. 



Cope gave, as one character separating this species from the others then described, the 

 thinness of the bones; but they appear to be only a little thinner than those of A. beatus. 



The hyoplastron just behind the entoplastron is 13 mm., that of A. beatus, 14 mm.; just 

 in front of the axillary notch, 14 mm., that of A. beatus, 17 mm.; medially at the front of the 

 xiphiplastron, 16 mm., in A . beatus, 17 mm. 



The humero-pectoral sulcus falls behind the entoplastron. The abdominal scutes meet 

 along the midline for a distance of 105 mm.; the femorals, 87 mm.; the anals, 76 mm. The 

 inframarginals on the bridge are long and narrow, the middle one being 80 mm. long and 

 16 mm. broad. The median longitudinal sulcus runs a very irregular course, especially in the 

 hinder half of the plastron. 



The whole lower surface of the plastron is ornamented with a sculpture which consists 

 of very shallow, somewhat elongated depressions separated by low rounded walls. The pits 

 alternate somewhat and are arranged more or less in rows. These run usually in a longitudinal 

 direction. The sculpture is much like that of A. beatus and A . punctatus, and reminds us of 

 Cope's description of that of Basilemys imbricaria, but the pits are not nearly so deep as in the 

 latter species. 



Adocus pravus Leidy. 



Emys pravus, LEIDY, Proc. Acad. Nat. Sci. Phila. 1856, p. 303; Smithson. Contrib. Knowl., xiv., art. 



vi, 1865, pp. 108, 120, plate xix, fig. I. 

 Adocus pravus, COPE, Proc. Acad. Nat. Sci. Phila. 1868, p. 235; Cook's Geol. New Jersey, 1868 (1869), 



p. 734; Ext. Batrach., Reptilia, Aves N. A., 1870, pp. 129, 233, 234; Proc. Amer. Philos. Soc., 



XI, 1870, p. 297; Ibid., XII, 1871, p. 44; Vert. Cret. Form. West, 1875, p. 262. HAY, Bibliog. and 



Cat. Foss. Vert. N. A., 1902, p. 444. 

 Emys parva, MAACK, Palaeontographica, xvm, 1869, p. 278. 



The present species was discovered by Professor George H. Cook, State Geologist of New 

 Jersey, in the upper bed of Cretaceous greensand at Tinton Falls, Monmouth County, New 

 Jersey, and was described by Dr. Joseph Leidy. Originally the type consisted of most of the 



