THALASSEMYDID^. 14! 



Osteopygis borealis (Wieland). 

 Plate 26, fig. 3; text-figs. 163-171. 



Osteopygis sopita,CopE, Proc. Acad. Nat. Sci. Phila. 1868, p. 147; Vert.Cret. Form. West, 1875, p. 258. 



HAY, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 441. 

 Prophura sopita, COPE, Cook's Geol. New Jersey, 1868 (1869), p. 735; Amer. Naturalist, in, 1869, p. 88; 



Ext. Batrach., Rept., Aves N. A., 1869, pp. 140, 235, p. vii, figs. 4-7, text-fig. 39. 

 Prophura borealis, WIELAND, Amer. Jour. Sci., (4) XVH, 1904, p. 129, pi. ix; ibid, xvm, 1904, p. 190, 



fi g- 4- 



Under Osteopygis sopitus the writer has presented his reasons tor concluding that Cope 

 erred when he referred to that species the specimen of Osteopygis which he described in his 

 Extinct Batrachia, etc., p. 140, plate vii, figs. 4-7. 



The type of Wieland's Prophura borealis is No. 778 of the Marsh collection, in the Yale 

 University museum. It was obtained in 1870, from the upper bed of greensand, near Horners- 



iscK 



FIG. 163. Osteopygis borealis. The humerus, and parts of carapace, plastron and pelvis. Xj. 



c p I c p 2, etc., costal plates; hum, hurnerus ; hyo, hyoplastron ; hypo, hypoplastron ; //, ilium ; uch, ischmtn; 

 . i, n, 2, first and second neurals; nu. p, nuchal plate; pub, pubis; xiph, xiphiplastron. I, 2, 3, etc., ri] 

 and left peripherals. 



town, Monmouth County, New Jersey. It furnishes the nuchal and the first and the second 

 neural; the second, third, fifth, sixth, and seventh right peripherals; the first, second, 

 third, fifth, and sixth left peripherals; the first, second, fourth, and fifth right costals; the first 

 and second left costals; the right hyoplastron and hypoplastron; both xiphiplastra; the 

 left humerus; the left pubis and ilium; and both ilia. These bones are in a fine state c 

 preservation. 



