NATURAL SCIENCES OF PHILADELPHIA. 



January 2i tJi. 

 Vice President Bridges in the Chair. 



Forty members present. 



A paper entitled the Mexican Humming Birds, No. 1, by Rafael 

 Montes de Oca was presented for publication. 



Mr. Lea exhibited some specimens of Unionida?., and remarked that he had 

 often been asked as to the number of species which inhabited the United 

 States, a question he could not answer, as he had never made a separate cata- 

 logue of such species. Recently he had been requested by the Secretary of the 

 Smithsonian Institution to furnish a list for publication by that Institution, 

 which he had just finished and sent to Washington. In making the list he 

 had used the manuscript which he had prepared for a new and enlarged edi- 

 tion (4) of his " Synopsis. " From the list he had carefully eliminated the 

 synonyms, and there remained in it the extraordinarily large number of 

 five hundred and twenty species which have been described, inhabiting the 

 Rivers, Lakes and Pools of the United States and Territories, and he stated 

 that he had some 30 to 40 in his possession not yet named or described. 

 These 520 may be thus divided : 



Unio, ......... 441 species. 



Margaritana, ....... 26 do. 



Anodonta, ........ 53 do. 



520 

 New species in Mr. Lea's possession, but yet not described, 30 



550 

 Mr. Lea further remarked that it was very probable that at least 100 more 

 species would be added to this list, as inhabiting within the present limits of 

 the United States, as almost every naturalist, searching in unexplored waters, 

 was constantly discovering new forms. In reflecting on the profusion of this 

 kind of animal life in the United States, the naturalist is astonished at the 

 great number of forms characteristic of the various species, and he is the more 

 struck with the extent of it, when a comparison is made with the small num- 

 ber of species which inhabit the continent of Europe, there not being in the 

 fresh waters of that quarter of the globe more perhaps than ten species, viz: 

 seven Uniones, one Margaritana, one Monocondylcca, and one Anodonta. Mr. 

 Lea stated that he had taken great pains to procure specimens from all parts 

 of Europe, and he was satisfied that there were 98 synonyms made by Euro- 

 pean authors, for the single species of Anodonta cygnea, Draparnaud, the 

 Mytilus cygneus of Linnaeus, and the synonymy is nearly as profusely erroneous, 

 in Unio pictorum, Unio tumidus, Unio Batavus and Unio littoral is. 



Mr. Slack remarked, in connection with the bones presented this evening, 

 that they were discovered some two weeks since by Mr. O. C. Herbert, in his 

 marl pits, near Marlborough, Monmouth Co., N. J., at a depth of twenty-five 

 feet beneath the surface. Having received information of their discovery from 

 Mr. Hopper, of Freehold, on Monday week, Mr. S. visited the pits and pro- 

 cured the specimens from Mr. H. They consist of fragments of the femur 

 and fibula of the Mosasaurus, and are of great interest, the long bones of this 

 reptile having until recently been unknown. 



On motion of Mr. Slack, the thanks of the Academy were ordered 

 to be tendered to Messrs. J. M. Hopper and O. C. Herbert, of Mon- 

 mouth Co., N. J., and also to Mr. Edward L. Perkins, for donations 

 presented by them. 



I860.] 



