BOTHREMYDID^-:. 



Bothremys cooki Leidy. 

 Plate 23, figs. 2, 3; text-figs. 96, 97. 



I0 3 



Bothremys cooki, LEIDY, Smithson. Contrib. Knowl., xiv, art. VI, 1865, pp. no, 120, plate xviii, figs. 

 4-8- COPE, Cook's Geol. New Jersey, 1868 (1869), p. 735; Amer. Naturalist, in, 1869, p. 89; 

 Ext. Batrach., Reptilia, Aves N. A., 1870, p. 157; Vert. Cret. Form. West, 1875, p. 263. MAACK, 

 Palaeontograph., xvm, 1869, p. 280. BAUR, Ann. and Mag. Nat. Hist. (6), iv, 1889, p. 38. HAY ^ 

 Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 438. 



The skull which has furnisht all that we know of this species is a most extraordinary one. 

 It was found in the lower bed of greensand, belonging to the upper Cretaceous, near Barnes- 

 boro, Gloucester County, New Jersey, and is now in the geological collection of Rutger's 

 College, New Brunswick, New Jersey, where the writer has been permitted to examine it. It 

 was fully described and figured by Leidy in his original description. His figures are stated 

 to be of the size of nature, but they are really somewhat reduced. Plate 23, figs. 2, 3, of the 

 present work is reproduced from drawings belonging to the U. S. Geological Survey. These 

 were prepared in 1888 for Dr. George Baur, who was then preparing to monograph the fossil 

 turtles. The one showing the lower surface of the skull differs from that of Dr. Leidy in 

 indicating the positions of the sutures. It will be observed that in this drawing the missing 

 quadrate regions are restored in outline. 



The skull, from the tip of the snout to the occipital condyle, had originally a length of 

 close to 70 mm. The width at the hinder end of the maxillae is 70 mm. From the latter point 



FIGS. 96 AND 97. Bothremys cooki. Skull of type. Xjf. 

 96. Seen from above. 97. Seen from right side. 



the outline of the skull rounds rapidly to near the end of the snout. Just before this is reacht 

 the curves change somewhat, so that the snout is slightly prolonged. The skull is flat above 

 (text-figs. 96, 97) there being a slight descent from the orbits forward. The Jnterorbital 

 space is 17 mm. wide. The eyes lookt strongly upward. Both diameters of the orbits 

 measure 14 mm. From the upper borders of the orbits the sides of the face sloped downward 

 and outward with a moderate curvature. The outline of the upper jaw, seen from the side, 

 is very convex. The nasals are absent. Whether or not the temporal region was widely 

 rooft over is uncertain, but it is probable that such was the case. 



A view of the lower surface of the skull shows many interesting features. The premaxillae 

 are large, extending backward a distance of 18 mm. Behind these comes the well-developt 

 vomer, which presents feeble palatine plates, to aid in underflooring the nasal passages. 

 The length of the vomer as seen from below is 15 mm. It lacks much of reaching the 

 pterygoids. The palatines meet the vomer in advance of the choanae. The anterior borders of 

 the choanae are placed 24 mm. behind the tip of the snout. These choanae lie in a vaulted 

 excavation, which, beginning on the premaxillae and expanding backward, reaches to the post- 

 palatine foramina, being shallow in front of the choanae. The excavation is bounded on each 

 side by a prominent tootht ridge, the inner boundary of the triturating surface of the jaw. 

 The pterygoids meet along the midline a distance of only 7 mm. As in the Pleurodira gener- 



