376 



FOSSIL TURTLES OF NORTH AMERICA. 



HG. 472. HaJnatius majusculus. 

 Plastron of type. X J. 



The entoplastron appears to have been of the same form as in H. corsoni. Its length is 

 80 mm., its width 120 mm. The length of the bridge is 206 mm. 



On account of lateral crushing the width of the posterior lobe can not be accurately 

 determined. Its length is 175 mm. It is conspicuously notcht behind, the depth of the notch 

 being 45 mm. 



The gular scutes probably overlap slightly the entoplastron, but this is not certain. The 



humero-pectoral sulcus skirts the hinder border of the 

 entoplastron. The pectoral scutes have a form quite differ- 

 ent from that of H. corsoni. They are narrow just 

 mesiad of the axillary notch, but grow wider as they 

 approach the midline, attaining there a width of 75 mm. 

 At the midline the abdominals have a fore-and-aft extent 

 of 140 mm., the femorals 80 mm., the anals about 55 mm. 

 The sulci of the plastron are rather narrow and shallow, but 

 those of the bridge lie in deep grooves. 



This species differs from H . corsoni in several respects. 

 The most conspicuous is perhaps the height of the periph- 

 erals, especially those above the bridges. The form and 

 width of the pectoral scutes too is distinctive. The bridge 

 appears to be shorter in comparison with the length ot 

 the anterior lobe. The hinder borders of the carapace 

 are more scallopt than in H. corsoni. 



Prof. E. D. Cope referred some remains of Hadri- 

 anus from the Wasatch of New Mexico to H. corsoni; while 

 other remains he regarded as a distinct species, which, 

 however, he did not name. His specimens appear to be 

 lost. It is doubtful whether any of them belonged to the 

 Bridger species. 



Hadrianus majusculus is interesting because of the fact that it is the oldest-known repre- 

 sentative of the family Testudinidae. 



Hadrianus corsoni (Leidy). 

 Plates 60, 61 ; text-figs. 473-479. 



Testudo corsoni, Leidy, Proc. Acad. Nat. Sci. Phila. 1871, p. 154; U. S. Geol. Surv. Montana, etc., 



1872, p. 366; Proc. Acad. Nat. Sci. Phila. 1872, p. 268; Contrib. Extinct Vert. Fauna West. Terrs., 



1873, pp. 132, 339, plate xi, figs. 1,2; plate xv, fig. 7; plate xxix, figs. 2-4; plate xxx, figs. 1-4. 

 Emys carteri, Leidy, Proc. Acad. Nat. Sci. Phila. 1871, p. 228; Amer. Jour. Sci., (3) II, 1871, p. 372; 



U. S. Geol. Surv. Mont., etc., 1872, p. 367; Contrib. Ext. Vert. Fauna West. Terrs., 1873, pi. xi. 



Testudo hadrianus, Cope, Paheont. Bull. No. I, 1872; Proc. Amer. Philos. Soc, XII, 1873, p. 463. 



Hadrianus quadratus, Cope, Proc. Amer. Philos. Soc, xii, 1873, p. 468. 



Hadrianus octonarius, Cope, Palaeont. Bull. No. 2, 1872; Proc. Amer. Philos. Soc, XII, 1873, p. 468; 

 U. S. Geol. Surv. Terrs., 6th. Ann. Rept., 1872 (1873), p. 630; Amer. Naturalist, XVI, 1882, p. 992, 

 figs. 11 13; Vert. Tert. Form. West. 1884, p. 140, plate xx, figs. 1-4. Osborn, Scott, and Speir, 

 Pal. Rept. Princeton Sci. Exped. 1877, p. 95. Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902^.450. 



Hadrianus corsoni, Cope, U. S. Geol. Surv. Terrs., 6th. Ann. Rept., 1872 (1873), p. 631; ?Syst. Cat. 

 Vert. Eocene N. Mex., 1873, p. 36; ?Ann. Rept. Chief Engineers, Explor. W. 100th Merid., 1875, 

 p. 1016 (of separata, p. 96); .'Wheeler's Rept. U. S. Geog. Surv. W. 100th Merid., IV, 1877, p. 58, 

 plate xxiv, figs. 36, 37; Amer. Naturalist, xvi, 1882, p. 992; Vert. Tert. Form. West, 1884, p. 141. 

 Hay, Bibliog. and Cat. F"oss. Vert. N. A., 1902, p. 450; Amer. Geologist, xxxv, 1905, p. 333. 



This species was based on the anterior portion of a plastron which was discovered by Dr. 

 Corson at the Grizzly Buttes, about 15 miles south of east of Fort Bridger, Wyoming, and 

 which was sent for study to Dr. Leidy. This was figured by the latter author in his Contribu- 

 tions to the Extinct Fauna of the Western Territories, plate xv, fig. 7, and is in the Academy 

 of Natural Science, at Philadelphia. In 1871 Dr. Leidy made a trip to Fort Bridger and 

 obtained a number of specimens of the same species, and these added much to the knowledge of 

 the animal. Among the remains secured was a large plastron which, on account of post- 

 mortem injury to the lip. Dr. Leidy did not recognize and which be made the type of the species 



