1856.] 303 



Notices of Remains of Extinct Turtles of New Jersey, collected by Prof. Cook, of the 

 State Geological Survey, under the direction of Dr. W. Kitchell. 



By Joseph Leidy, M. D. 



1. Chelone gkand^va, Leidy, Proc. Acad. Nat. Sci. v. 329. 



Originally founded on three vertebral plates from the Miocene marl of Salem 

 CO., N. J. The collection of the N. J. State Geological Survey contains several 

 costal plates broken into numerous fragments, three anterior marginal plates, 

 and a hyosternal plate also broken into many fragments. A median costal plate 

 restored, measures 8i in. long to the projecting portion of the rib, which is lost, 

 3^ in. wide and J in. thick. The marginal plates, convex above and at the 

 outer border, and acute within, are 4J in. long, 2f wide and 1 in. thick. The 

 broken hyosternal preserves its length, which is 10 in. from the anterior point 

 to the posterior suture. One of the vertebral plates above mentioned, ia 2f 

 in. wide, 2\ in. antero-posteriorly and ^ an inch thick. 



The surfaces of all the bones are smooth. The estimated length of the cara- 

 pace is about 35 to 40 inches, the breadth about 30 inches. 



The same collection contains fragments of several lateral and posterior margi- 

 nal plates of a marine turtle, about the size of that just indicated, but the spe- 

 cimens were obtained from the cretaceous Green Sand formation of Monmouth co. 

 N. J. The specimens have a thick grooved inner border, and gradually become 

 thinner until they terminate in an acute outer border. They are slightly curved 

 upwardly, and their surfaces are smooth. One of the plates has an entire length 

 of 3| inches ; and is 3j inches broad by f of an inch thick at the inner border. 

 Another plate is 4|^ in. long, 2 J in. wide and f of an in, thick internally. 



2. Emts firmcs, Leidy. 



In company with the latter were found the third, sixth and seventh marginal 

 plates of the left side ; the sixth, seventh and eighth of the right side, and 

 portions of the left hyosternal and the right hyposternal plates of a species of 

 Emys. 



The surfaces of the bones are nearly smooth, and those of the sternum are of 

 great thickness. The seventh marginal plate from its upper border to its acute 

 edge measures 3J in., and transversely 2| in. The two eternal plates in the 

 median line are each about 3 in. long, and in the same position are from 7 lines 

 to 1 inch in thickness. 



3. Emys prayus, Leidy. 



Found with the remains of the preceding species, there are the greater portions 

 of a right hyosternal and a left hyposternal plate of a second species. Surfaces 

 without distinct marks of the scutes, and presenting an eroded appearance. 

 Median suture irregular in its course ; and that between the hyo- and the hypos- 

 ternals is even more irregular. Length of each plate in the median suture 5J 

 inches; thickness from 5 lines to half an inch. Breadth of ento-sternal space 2| 

 inches. 



4. Platemys sulcatus, Leidy. 



Specimens of the fifth, sixth and seventh left marginal plates found with the 

 preceding remains of Emys apparently indicate a species of the subgenus Plate- 

 mys. The three bones together measure along their acute margin 8 inches. The 

 seventh plate is 3 inches antero-posteriorly and 2^ high. 



The surface of the plates is marked with tortuous grooves. 



5. Chelone ornata, Leidy. 



The collection of this Academy contains portions of two lateral marginal 

 plates of a marine turtle from the green sand of Burlington co.,N. J., where they 

 were discoved by Mr. L. T. Germain. The bones are wedged-shaped in trans- 



