PROCEEDINGS 



or THE 



ACADEMY OF NATURAL SCIENCES 



OF PHILADELPHIA. 



January 3d y 1854. 

 Mr. Lea, Vice-President, in the Chair. 



Letters were read : 



From Baron J. W. Yon Miiller, dated Brussels, Nov. 23d, 1853, 

 transmitting the works announced this evening, and also making en- 

 quiries respecting the feasibility of establishing a Zoological Garden in 

 Philadelphia. 



From Prof. John Le Conte, of Athens, Georgia, acknowledging the 

 receipt of his notice of election as a Correspondent. 



From Mr. Isaac Lea, dated Philadelphia, Dec. 30th, 1853, returning 

 acknowledgments for his election as a Vice-President of the Academy. 



A paper was presented for publication in the Proceedings, entitled 

 " On a new Entomostracan of the family Limnadidae, inhabiting the 

 Western waters. By Charles Girard." Beferred to Drs. Leidy, Bridges 

 and Buschenberger. 



A paper intended for publication in the Proceedings, entitled " On 

 the Ancient Alluvium of the Ohio Biver and its Tributaries, by Alfred 

 T. King, M. D.," was read and referred to Mr. Vaux, Mr. Lea, and Dr. 

 Buschenberger. 



Mr. Lea exhibited to the Academy a specimen of D'Orbigny's Acostcea giia- 

 d/casa?ia, which he owed to the kindness of that distinguished zoologist, during 

 Mr. Lea's visit to Paris last year. This genus he reminded the members was 

 identical with the Mulleria of Ferussac, as he formerly suggested, and was 

 afterwards satisfied to be the case on seeing the original specimen, described by 

 Ferussac in 1823, which is now in the fine collection of Mr. Delesert in Paris. 

 Mr. Lea stated that although the specimen figured by D'Orbigny had quite a 

 length of stem connecting the young portion of the shell, the Anodonta form, 

 with the mature portion, the Ostrea form, yet this was not necessarily or uni- 

 formly so. In the case of his own specimen this was very different. It hap- 

 pened, as is sometimes the case with the genus Ostrea, a. dead valve was filled up 

 by a subsequent living individual ; and on close examination, there were really dis- 

 covered to exist two specimens of the Anodontiform age ; one on the old single 

 valve at one end, and another on the reverse end appertaining to the living speci- 

 men, having the epidermis on it perfect. Neither of these specimens had a stem, 



PROCEED. ACAD. NAT. SCI. OF PHILADELPHIA, VOL. VII., NO. I. 1 



