,-s 



UNIO. 



c 

 X 

 p 



X 



o 



WIDE. 



*viridulus. Lea. 



*anodontoides. Lea. Kirtl. Chenu. 



Adams. Han. 

 Unio teresf Raf. 

 Unio teres. Con. 



*rasus. Lea. 



*parallelopipedon. Lea. D'Orb. Han. 



*acutirostris. Lea. 



*platyrhynclms. 1 Rossm,. Schmidt. 

 Potier. Par. Villa. Han. 



*Cailliaudii. Fer. H. Adams. 

 Unio lithophagus. Zierj. 

 Unio teretiusculus. Phili. 



*Ingallsianus. Lea. 

 *sagittarius. Lea. Von Mart. 



*tumidus. 2 Retz. Speng. Schum. Nils. 

 Pfeif. Villa. Rossm. Brown. 

 Menke. Stein. Put. Potier. Dup. 

 Forbes. Mouss. Fitz. Han. Moq. 

 Caill. 



li 



WIDE. 



Unio ovalis. Retz. Flem. 



Villa. Brown. Gray. Caill. 

 My a ovalis. Monta. 

 Mya ovata. Don. Mat. Wood. Dill. 

 Mya depressa. Don. 

 My sea solida. Turt. 

 Mysca ovata. Swain. 

 Unio nodulosa. Lam. Menke. 

 Unio Michaudiana? Des Moul. Dup. 

 Unio ovata. Studer. Bouil. Menke. 



Fitz. 



Unio rostrata. Stud. 

 Unio Limagnse. Bouil. 

 Unio solida. Villa. 

 Unio arcuatus. Bouch. 



*pictorum. 3 Retz. Speng. Lam. Cuv. 

 Mill. Pfeif. Drap. Base. Don. 

 Blain. Crouch. Flem. Des Moul. 

 Grat. Bouil. Menke. Nils. Stein. 

 Brard. Brown. Puton. Desh. Po- 

 tier. Por. Dup. Klees. Merm. 

 Kiist. Alder. Graells. Villa. 

 Forbes. Schmidt. Rossm. Guerin. 

 Morelet. Gras. Goupil. Bouch. 

 Schrenk. Fisch. L. Waard. Fitz. 

 Midd. Gras. Gerst. H. & A. 

 Adams. Moq. Han. Caill. 



1 This is a curious and very interesting shell which I received from Vienna. Its habitat is Carynthia. 

 It may be only a remarkable variety of pictorum, Eetz. Such is the opinion of some of the German 

 malacologists. 



2 The tumidus, Retzius, is, I think, without doubt, the same as ovalis, Retzius, and other European 

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

 Prof. Mousson gave me in Zurich a specimen of this species, which, he says, came from Java. 



3 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 Malacology. I have seen no reason to change my opinion, since the publication of the last 

 edition of this SjTiopsis, 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 

 iu Europe have endeavored to stem this tendency to multiply so dreadful a synonymy, such as U. picto- 

 rum 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 Rossmaessler 

 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.) 



