NATURAL SCIENCES OF PHILADELPHIA. 91 



March lbth. 



Vice-President Bridges in the Chair. 



Fifty members present. 



The following were presented for publication in the Proceedings : 



Notes on Coluber calligaster S ty, and description of new species 

 of Serpents in the collection of the North-western University of Evans- 

 ton, 111. By R. Kennicott. 



Ichthyological Notices. By Charles Girard, M. D. 



And were referred to Committees. 



The Proceedings of the Academy for February was laid on the table 

 by the Committee. 



Mr. Foulke announced the death, at Rome, on the 13th alt., of Charles 

 F. Beck, M. D., late a member of the Academy. 



March 22d. 

 Vice-President Bridges in the Chair. 



Forty- four members present. 



The following was presented for publication in the Proceedings : 



Catalogue of Birds collected on the rivers Camma and Ogobai, West- 

 ern Africa by Mr. P. Duchaillu, in 1853, with notes and descriptions 

 of new species. By John Cassin. 



And was referred to a Committee. 



Dr. Leidy called the attention of the members to the tooth of the Mastodon, 

 from Tambla, Honduras, presented by Capt. J. M. Dow, this evening. It is a 

 last superior molar, and presents a greater degree of developement of the inter- 

 vening accessory lobes of the crown than is usual in the teeth of Mastodon 

 ohioticus, but it nevertheless mo3t probably belongs to the same species. 



Dr. L. then directed attention to the fine collection of teeth and fragments of 

 jaws of Mosasaurus, from the Green Sand of Monmouth Co., New Jersey, pre- 

 sented by Mr. J. H. Slack, and other gentlemen through him. The specimens 

 illustrate, in a striking manner, the mode of development and succession of the 

 teeth, noticed some time since in the Proceedings, (L857, p. 176). The speci- 

 mens further exhibit variations in form and size, though obtained from the same 

 individual. The teeth, with conical crowns and polyhedral sides, are those usu- 

 ally viewed as characteristic of Mosasaurus. Others had been referred to the 

 genus Geosaurus ; and such as were much compressed with trenchant borders, 

 and without planes, were viewed as characteristic of the genus Leiodon. 



The large humerus, presented by Mr. M. P. Rue, through Mr. Slack, was not 

 found in the same marl pit as the Mosasaurus, though in the same formation not 

 far distant. It bears a strong resemblance in form and size to the correspond- 

 ing bone of Iladrosaurus, though presenting sufficient anatomical difference to 

 belong to another genus. It perhaps belongs to Mosasaurus; the bones of the 

 extremities of this animal yet remaining unknown. 



Dr. L. added he was inclined to suspect that all the remains of Mosasaurus 

 hitherto discovered in America belonged to one species, at least there appears 

 insufficient evidence to separate them. Perhaps, however, the remains of the 

 Mosasaurus, discovered in the green sand of the western portion of the conti- 

 nent, may indicate a different species from those obtained from the eastern por- 

 tion. 



1859.] 



