240 [December, 



Many years ago the distinguished zoologist, Mr. Swainson, sent to me from Lon- 

 don, for the purpose of identification, a numher of Uniones, which he had received 

 from Rafinesque, but of which he could make nothing. The confusion of pieces of 

 valves and names formed such a mass as utterly to defy any attempt at recogni- 

 tion of his species. I returned them, totally unable to identify them with any 

 satisfaction. Dr. Ward said that Rafinesque's descriptions and outline " would 

 equally well apply to six or eight different species." These facts fully account 

 for the difference of judgment between Mr. Say and Mr. Conrad in their Synopses, 

 both published in this city, dated April 1834. Even they with the 'specimens be- 

 fore them marked by Rafinesque himself, could not agree in very many cases. 

 Mr. Say considered that caslaneus, Lea, was lecvigatus, Raf., while Mr. Conrad 

 placed lens, Lea, as asjnonym to Icevigatus. Mr. Say makes zigzag, Lea, and do- 

 naciformis, Lea, synonyms to nervosus, Raf., while Mr. Conrad doubts that zigzag 

 is synonymous with nervosus, and makes do naciformis synonymous with truncatus, 

 Raf., which (donactformis) in his appendix, the next year, he considers a distinct 

 species, but which in the new synopsis of 1853 he placed with zigzag, as synony- 

 mous with nervosus, Raf.! 



Without going further into long statements of discrepancies between Mr. Say 

 and Mr. Conrad in regard to establishing Rafinesque's species, it will be enough 

 to say that in the Synopsis of Mr. Say it will be found that out of sixty-one des- 

 criptions by Rafinesque he gives him thirty-eight species, and by comparing 

 these with the new Synopsis of Mr. Conrad, eighteen of them are more or less 

 different in their synonymy, or are entirely dismissed from the list of species.* 



Not wishing to devote too much time or space to tracing out the changes of 

 of opinion by Mr. Conrad from time to time in attempting to substantiate Ra- 

 finesque's species, it will be sufficient to trace a single one through the various 

 sinuosities which he has carried it to this period. I do not know how many there 

 may be like it, but I think it ought to be sufficient to satisfy any one, that syno- 

 nyms based on such uncertain authority ought to be most carefully scrutinized. 

 The " synoptical table of the species of American Naiades with Synonyms," 

 April 1834, was got up by Mr. Conrad with a view, he says, to u rectify the con- 

 fused nomenclature of American Naiades." How successfully this has been car- 

 ried out may be seen by tracing this only one which I have attempted to follow en- 

 tirely through with its connections. In the list of species (p 72) Mr. Conrad 

 sets down U. triangularis, Raf. as an established species, and adds as synonyms 

 lateralis Raf, sintoxia Raf., pachostea Raf., mytiloides Raf, ruber Raf. and pyrami- 

 datus Lea. Eighteen months afterwards, this u retification of confused nomen- 

 clature, was found to require itself a rectification, and we find in an appendix 

 dated Oct. 1835, under the caption of additions to and corrections of, the catalogue 

 of species of American Naiades," that ruber Raf. is not a synonym to triangularis, 

 but really a species, and that pyramidatus Lea, is a synonym to it ; also, that 

 pachostea Raf. was erroneously placed as a synonym to triangularis Raf., it too 

 oecoraes a type, and Cooperianus Lea, is assigned as a synonym to it. Mytiloides 

 likewise is no longer a synonym to triangularis, but it becomes one to clavus 

 Lam. The other three are as yet still considered synonyms to the type triangula- 

 ris might be better to cite a few of those to show at a glance, how much dis- 

 crepancy of opinion there is between Mr. Say and Mr. Conrad, and to show how 

 dangerous it is to science to admit such "guessing" where nothing should be 

 set down as certain that could not bear the test of scrutiny. 



Mr. Conrad says it is incrassatus Lea. 



' " subangulatus Lea. 

 " foliatus Hild. 

 " " solidus Lea. 

 " " striatusRaf. 

 does not admit triangularis as 



a species. 

 " " " cuneatus as a 



species. 

 " " " gibbosus as a 

 species, 

 torulosus Raf. is not admitted by Mr. Say as a species. Mr. Conrad says it is gibbosus Raf. 



and perplex us Lea. 



