92 



PROCEEDINGS OF THE ACADEMY OP 



burial ground on Arch street, fibove 5th. As it had to be remored on the 

 closing up of that ground, it was thought best to replace it by a new one, 

 and the bent stone was given to the Academy on the 15th of November, 

 1867. The stone is of white Pennsylvania marble and is 6 ft. 3i in. long, 

 by 3 ft. 1 in. wide and 2 in thick. It simply rested on six marble posts, 

 without being fastened to them, except imperfectly by mortar, and must have 

 bent merely from its own weight. The posts stood on separate brick foun- 

 dations under ground, but the near (northern) middle post of the picture 

 had sunk so as no longer to touch the slab, and the other middle post had 

 settled also. The space between the inner sides of the end posts, lengthwise 

 of the slab, was 4 ft. 9^ in. The stone is bent down in the middle an inch 

 and a half from a straight line drawn from the near right hand corner to the 

 far left hand corner (northwest and east) and half an inch from the line 

 drawn cornerwise the other way ; and lengthwise through the middle it is 

 bent an inch and a sixteenth from straiahtness. 



3Iarch 24th, 1868. 



The President, Dr. Hays, in the Chair. 



Forty-two members present. 



The following was presented for publication : 



"Sexual Law in Acer dasycarpum." By Thos. Meehan. 



Prof. Cope exhibited to the Academy several fragments of a large Enalio- 

 saurian, discovered by the Academy's correspondent at Fort Wallace, Kansas, 

 Dr. Theoph. H. Turner. Portions of tv?o vertebi-je brought east by Dr. Le Conte 

 from his geological survej^ of the Pacific Railroad route, had previously indi- 

 cated to the speaker the existence of an animal related to the Plesiosaurus, and 

 the recovery of the greater part of the reptile had confirmed this affinity. 



The remains consisted of over one hundred vertebriB, with numerous por- 

 tions of ribs, the greater part of the pelvic and scapular arches, with two long 

 bones somewhat like femora. Part of a muzzle, with teeth, belonged to the 

 same animal. 



The species represented a genus differing in important features from Plesio- 

 saurus and its near allies. These were the absence of diapophyses on the 

 caudal vertebrae, and the presence of inferiorly directed plate-like parapophy- 

 ses, which took the place of the usual chevron bones, in the same position ; 

 also in the presence of chevron-like bones on the inferior surfaces of the cervi- 

 cal vertebrae ; further in some details of the scapular and pelvic arches. The 

 diapophyses of the dorsal vertebras originated from the centrum, and not from 

 the neural arch. 



In generic features it was related to the Cimoliasaurus and Brimosaurus of 

 Leid)', so far as the latter are yet known. It differed from both of them in 

 lacking diapophyses on the lumbar vertebrte. 



The general form was dif!erent from Plesiosaurus in the enormous length of 

 the tail, and the relative]}- shorter cervical region. The total length of the ver- 

 tebral column sent was thirty-one feet ten inches, divided as follows: caudals 

 18 ft. 10 in., dorsals 9 ft. 8 in., cervicals 3 ft. 4 in. ; adding for missing cervi- 

 cals and cranium at least 2 ft. 6 in., we have a total of 34| feet. An interval 

 of three to four feet occurred between the cervicals and dorsals as they lay in 

 the cliff from which they were excavated, which if, as is probable, it was occu- 

 pied by vertebrae in the animal, would give a length of thirty-eight feet. The 

 caudal vertebrje had very compressed centra, and elevated neural and haemal 

 laminae, and were of unusually elongate form. Neural arches everywhere on 

 the columa co-ossified. All the vertebrse considerably more constricted me- 



[March, 



