AND OTHER FAMILIES. 205 



rous, while the cygnea is viviparous. Should this prove true, they 

 must of course be considered distinct. 



Anodonta sulcata. I saw in the Duke de Rivoli's cabinet the spe- 

 cimen described by Lamarck. It is a variety of the A. cygnea. and I 

 presume is from Europe. The cygnea has no analogue in the United 

 States, with which I am acquainted. 



Anodonta fragilis. Baron de Ferussac gave me a specimen of this 

 species, brought by Monsieur Lapylaie from Newfoundland. When 

 I first saw it in Paris, I recognized it instantly to be similar to speci- 

 mens I had found in lake Skaueateles, nearly six years since, but which 

 I had not yet published. 



Anodonta rubens. This interesting species is perhaps the most pon- 

 derous of the genus. It inhabits the Nile as well as the Senegal. My 

 specimen, from the latter river, is heavier and more inflated than those 

 which I have from the Nile. Deshayes places it in the genus Iridina, 

 asserting that the animal differs from the Anodonta, and is similar to 

 that of the Iridina. 



Anodonta crispata. This is a distinct and beautiful species, peculiar 

 for its transverse furrows. I owe to the kindness of Baron de Ferussac 

 the possession of this rare shell, the habitat of which is Cayenne. 

 Lamarck says, " d^ms les rivieres des regions australes ?" 



Anodonta imiopsis is a distinct species, and probably from New 

 Holland. 



Anodonta Pcnnsylvanica. I examined the specimen described by 

 Lamarck. It is in the cabinet of the Duke de Rivoli, and is the same 

 with the undulafa of Say, rugo.siis of Swainson. 



Anodonta intermedia is a variety of anatina. The intermedia of 

 Pfeitfer is a variety of cygnea. 



Anodonta trapezialis. The specimen described by Lamarck is in 

 the Garden of Plants. It is the giganteus of Spix, w^ho figures it in 

 his beautiful work. Its habitat is Brazil. Lamarck says, "des eaux 

 douces etrangeres a celles de I'Europe?" It is less transverse, and has 

 more volume than the following, which it closely resembles. 



Anodonta exotica. I examined specimens of this species in the 

 cabinets of the Duke de Rivoli, Baron de Ferussac and the Garden of 

 Plants. Lamarck's habitat says, "les rivieres de I'lnde?" I believe 

 54 



