122 



PROCEEDINGS OF THE ACADEMY OP 



November 1st. 

 Wm. S. Vaux, Vice-President, in the Chair. 

 Twenty-nine members present. 



Prof. Leidy exhibited the tooth of a reptile which had been submitted to 

 his examination from the Smithsonian Institution. The specimen, he ob- 

 served, was especially interesting, as it apparently pertained to a mosasau- 

 roid, and was obtained from the miocene tertiary deposit of Gay Head, Mar- 

 tha's Vineyard. 



The crown of the tooth is curved conical, and is without divisional planes. 

 The inner surface is only feebly defined from the outer, by a single imper- 

 fectly developed ridge postero-iuternally. 



The enamel is singularly roughened, due to short vermicular, somewhat 

 ramifying and more or less interrupted ridges, giving it a fretted or lettered 

 appearance. The transverse section of the crown is circular. 



The fang of the tooth, broken below and on the inner side so as to expose 

 the interior pulp cavity, is longer than the crown and very gibbous. It is 

 curved in the direction of the crown and is ovoidal in shape. The texture of 

 the fang appears as dense as ivory. No impress exists on the exterior of the 

 fang, resulting from contact with a successional tooth, but a deep groove oc- 

 cupies its inner side at the terminal extremity. 



The crown is broken at its apex, but when perfect has been about 16 

 lines long, measured on the outer side. The diameter at base is a little over 

 half the length. The fang has been about two inches long; its diameter is 

 17 lines. * 



The tooth evidently indicates an animal heretofore unknown to us, and I 

 therefore propose for it the name of Graphiodon yjnearius ; the generic term 

 having allusion to the lettered appearance of the enamel of the tooth. 



Prof. Leidy further remarked that he had recently received from Prof. 

 Hayden's expedition a collection of fossils, mostly consisting of remains of 

 turtles and crocodiles. He formerly had expressed surprise at the absence of 

 remains of the latter among the great profusion of remains of mammals and 

 turtles in the Mauvaises Terres deposits of White River and the sands of the 

 valley of the Niobrara River. He now felt some wonder at seeing so many 

 crocodilian remains, apparently of cotemporaneous age with some of the 

 latter. The reptilian remains are generally in a very fragmentary condition, 

 and bave been picked up from the surface of the country. Several unde- 

 scribed species of turtles were recognizable, but these would be characterized 

 at a later period. 



From among the crocodilian remains he had been able to obtain a large 

 portion of those of a skull of Crocodilos Elliotti, indicated a few evenings 

 ago from a jaw fragment. The skull appears to have nearly the form of that 

 of G- vulgaris and C. biporcalus. It is about a foot and a half in length. 

 Teeth appear to have been absent at the extreme fore part of the jaw. Im- 

 mediately behind their usual position the palate presents a deep pit at each 

 side of the naso-palatine orifice. The jaw is deeply indented laterally, just 

 back of the position of the fourth tooth, and a less indentation is situated 

 back of the ninth tooth. 



Prcf. Leeds called attention to a crystalline specimen of the variety of 

 Apatite called Staffelite, which he had not previously noticed in that condi- 

 tion. 



Mr. Willard made some remarks on a deposit of clay, of which a specimen 

 was presented this evening. The deposit, at White Hall, Bordentovvn, N. J., 

 had been found to be too hard and tough for digging, and required blasting 

 to be removed. 



[Nov. 



