36 



UN 10. 



WIDE. 



*strigosus. Lea. Ohenu. 



*perstriatus. Lea. 



*angustatus. Lea. Con. Chenu. 



*dactylus. Lea. Chenu. 



*lanceolatus. 1 Lea. Chenu. 



*anodontoides. Lea. Kirtl. Chenu. 

 TJnio teres? Raf. 



JJnio teres. Con. 



*parallelopipedon. Lea. D' Orb. 



*platyrhynchus. 2 Rossm. Schmidt. 

 Rotter. Ror. Villa. 



*Cailliaudii. Re?: 



Unio lithophagus. Zeig. 

 JJnio teretiusculus. Phili. 



*Ingallsianus. Lea. 



*tumidus. 3 Retz. Nils. Rfeif. Villa. 

 Rossm. Brown. Menke. Stein. 

 Put. Rotier. Rup. Rorbes. 



WIDE. 



Unio ovalis. Retz. Rlem. Sow. 



Villa. Brown. 

 Mytilus angustior. 4 List. 

 Mya ovalis. Monta. 

 Mya ovata. Ron. Mat. Wood. 



Rill. 

 Mya depressa. Ron. 

 Mysca solida. Turt. 

 Mysca ovata. Sivain. 

 Unio nodulosa. Lam. Menke. 

 Unio Michaudianaf Res Moul. 



Rup. 

 Unio ovata. Studer. Bouil. 



Menke. 

 Unio rostrata. Stud. 

 Unio Limagnse. Bouil. 

 Unio solida. Villa. 



*pictorum. 5 Retz. Lam. Cuv. Rfeif. 

 Rrap. Bosc. Ron. Blain. Crouch. 

 Rlem. Res Moul. Grat. Bouil. 

 Menke. Nils. Stein. Brarcl. 

 Brown. Ruton. Resh. Rotier. 

 Ror. Rup. Klees. Merm. Kiist. 

 Alder. Graells. Villa. Rorbes. 

 Schmidt. Rossm. Guerin. More- 

 let. Gras. Goupil. Rouch. 



1 M. Deshayes (2d edit. Lamarck) doubts if lanceolatus be not the young of anodontoides, "of Say." (Ano- 

 dontoides was not described by Mr. Say, but by myself.) The first has been found only in the waters east of the 

 Alleghany mountains, the last only in the western waters. There cannot be a doubt of their being distinct species. 

 In size they differ altogether. 



2 This is a curious and very interesting new species which I recently received from Vienna. Its habitat is 

 Carynthia. 



3 The himidus, Retzius, is, I think, without doubt, the same as ovalis, Retzius, and other European authors. 

 But, Retzius having described tumidus before ovalis, the former must take priority. 



4 Fide Fleming. 



5 The well-known Unio pictorum of European authors, so widely distributed throughout that quarter of the 

 globe, has been the fruitful source of trouble and perplexity to naturalists who have studied this branch of Mala- 

 cology. I have seen no reason to change my opinion, since the publication of the last edition of this Synopsis, as 

 to the synonymy, which, unfortunately, is still going on to increase, to the great embarrassment and injury of this 

 branch of the science. I am well aware that some able writers in Europe have endeavored to stem this tendency to 

 multiply so dreadful a synonymy as U. pictorum and An. cygnea present; and I find in the admirable work of 

 Forbes and Hanley (now nearly finished), on the Malacology of Great Britain, ideas which are so entirely parallel 

 with my own, that I cannot refrain from making the following extract. They say they "do not observe in Ross- 

 maessler figures of continental forms of this polymorphal shell, any of which our islands do not exhibit a nearly 

 analogous representation. If a certain platitude of language be demanded in a description of the preceding species, 

 far more requisite is it that our diagnosis of the present one should be sufficiently exclusive," p. 144. (See note 

 on An. cygnea.) 



