104 [October, 1841. 



Verbal Communications. Mr. Haldeinan called the at- 

 tention of the Academy to several specimens of Unio of vari- 

 ous colours, principally green and brown, the former being 

 referable to U. viridis of Rafinesque, the latter to U. Tappan- 

 ianus, of Lea. 



Mr. H. contends that they are identical, because they pass 

 into each other, both as regards colour and the peculiarities of 

 the cardinal teeth, which are lamellar, and extremely variable 

 in number and size. It was not necessary to add a synonym 

 to the original name, as Mr. Conrad proposed the name sub- 

 viridis (New Fresh- water Shells,) for the brown variety which 

 he figured ; in the event of its proving distinct from U. viri- 

 dis of the west. This method of proposing names is very 

 proper, because it has a tendency to limit the number of 

 synonyms which might might otherwise be inflicted upon the 

 nomenclature of natural history. Some contend that the 

 shell from the Susquehanna cannot be the viridis, because the 

 latter has not been found in the west, its locality being Ken- 

 tucky river, according to Rafinesque ; whilst the Tappanianus 

 is found in the Susquehanna ; but Mr. H. has found unequi- 

 vocal specimens in Pigeon creek, Kentucky, which cannot be 

 distinguished from those found in eastern Pennsylvania. He 

 has found a variety with a thick shell, in James river, Va. 

 Rafinesque's name has been objected to, but one of the speci- 

 mens exhibited presents as brilliant a green as that of Ano- 

 donta cataracta, Say. 



Mr. Haldeman wished the fact to be recorded, that he had 

 placed some living specimens of Western Unio, Unio rectus, 

 triqueter, circulus, cylindricus, ovatus and others, in the Sus- 

 quehanna, where no western species has hitherto been found, 

 except U. viridis, Raf. 



