1852.] 



January \^tli. 

 Vice-President Wetherill in the Chair. 



Dr. Leidy presented an additional portion of Mr. Dana's communica- 

 tion on the Crustacea of the hite American Exploring Expedition ; which 

 was referred as before to the original Committee. 



Mr. Wetherill stated that the Phosphate of Lime, a specimen of which 

 lie presented this evening, was being much used for agricultural pur- 

 poses, after being decomposed by the action of sulphuric acid. 



Mr. Wetherill also stated that the Adipocire, also presented this even- 

 ing, was the result of decomposition of the bodies of a number of sheep, 

 which had been buried fifteen years since in a wet soil, on a farm in an 

 adjoining county. 



Dr. Leidy, referring to the Ctetacean remains characterized by him 

 at the meeting of December 9th, remarked that they were the first relics 

 of Mammals that have been found in the Cretaceous Group. 



On leave granted, the Committee to which was referred Dr. D. D. 

 Owen's paper describing a new Mineral and a new Earth, presented a 

 report, recommending the same for publication in the forthcoming No. 

 of the Journal, which was adopted. 



January 27th. 



Mr. Ord, President, in the Chair. 



The Committee, to which was referred the following papers of Dr. 

 Le Conte, reported in favor of publication in the Proceedings. 



Notes on some Fossil Suillne Pachyderms from Illinois. 

 By John L. Le Conte, M. D. 



DiCOTYLES DEPRESSTFRONS. 



Hyops depressifrons Lee. Am. Journ. Sc. 2d series, Vol. 5, 103 (1848.) 



After a careful comparison of the fragments of this animal with Dicotyles 

 torquatus, I have come to the conclusion that the differences are by no means 

 of such a nature as to admit of the formation of a peculiar genus. 



The differences in the cranium which distinguish this animal from D. torquatus 

 are : 1st, the greater depression of the front ; 2d, the greater expansion and less 

 sudden declivity of the malar plates ; 3d, the less convex nasal bones. In con- 

 sequence of this last character, the groove running forward from the frontal 

 foramen is more or less superior in its whole extent and never lateral, as in the 

 anterior part of the head of D. torquatus. 



The lower part of the skull and the anterior part of the nose are broken away, 

 so that no teeth remain in the fragment. 



Accompanying this fragment are four teeth from the upper jaw, which differ 

 from the corresponding teeth of Platygonus compressus Lee., from the same 

 locality, by having the transverse ridges more distinctly connected with the 

 basal margin ; this is especially the case at the posterior margin ; the ridges also 

 show a tendency to unite together, and thus the transverse valley is rendered a 

 little narrower than in Platygonus. In all these points the teeth agree exactly 

 with Dicotyles torquatus, and on a careful comparison nothing worthy of notice, 

 even as a specific difference, could be detected. A part of the socket of the left 

 superior canine, with the adjoining portion of the palatal plate, shows no differ- 

 ence on comparison with D. torquatus. 



