APPENDIX. 265 



on the margin exhibiting the bands distinctly, labrum 

 simple, as much rounded above as below ; umbilicus small, 

 nearly closed. 



Greatest width one inch and nine-twentieths. 



Total length one inch and a half. 



Length of the aperture one and one-fifth of an inch nearly. 



Inhabits East Florida. 



During an excursion to East Florida, in company-with 

 Messrs. Maclure, Ord, and T. Peale, I obtained a single 

 dead and imperfect specimen of this interesting shell. It 

 occurred in a small creek, txibutary to St. John's river, and 

 on the plantation of Mr. Fatio. Captain Le Conte of the 

 Topographical Engineers, has since presented me with a 

 perfect specimen, with the information that he observed 

 them in very great numbers on the shores of Lake George, 

 a dilatation of St. John's river ; that in some places the dead 

 shells were piled up confusedly to a considerable height, 

 and that the Numenius longirostra feeds upon the living 

 animal. The spire is still less elevated than that of the 

 globosa of Swainson. PL 14, fig. 2. 



MELANIA. 

 M. virginica, nob. Falls of Niagara. 



ANODONTA. 



A. gibbosa. Shell thin and very fragile ; much inflated ; 

 anterior and posterior hinge-margins compressed, the for- 

 mer alated ; surface pale-yellowish testaceous, finely radi- 

 ate with green, and having somewhat regular concentric 

 minute undulations ; within somewhat iridescent 



