34 



OBLONG. 



famelicus. Cfould. 



*litoralis. Drap. Lam. Pfeif. Pes 



Moul. Gfrat. Brard. Desk. Guv. 



Maton and Racket. Bouil. Gras. 



Bronn. More. Mermet. Gassies. 



Goupil. Pupuy. Puton. Potter. 



Graells. 

 Unio crassus. Retz. Nil. Phili. 



Menke. Rossm. 

 Unio brevialis. Lam. 

 Unio semirugata. Lam. Menke. 



Chenu. 

 Unio nana. Lam. Pup. 

 Unio subtetragona. Mich. Pup. 



Merm. Graells. 

 Unio incurvus. Lea. Ghenu. 

 Unio Pianensis. Purines. Pup. 



Graells. 

 Unio granosus. Solium. 

 Unio brunneus. Bonhomme. 

 Unio Woolwichii. Morelet. 

 My sea ovataf Turt. 

 Mya rhomboidea. Schr. 



SUBROTUND. 



*circulus. Lea. 

 Mya rotundas 



Eat. Pesh. 

 Wood. 



Ghenu. 



*lens. 2 Lea. Ghenu. 

 *unicolor. Lea. 



rubellus. Con. 



Masoni. Con. K'dst. 



*rotundatus. Lam. 



Unio suborbiculata. Lam. Blain. 

 Unio glebulus. 3 Say. 

 Unio subglobosus. Lea. 



*Paranensis. Lea. P' Orb. 



Unio Solisiana (junior). P' Orb. 



membranaceus. 4 Lea. 

 Myt. membranacea. Mat. 

 Unio Matoniana. P' Orb. 

 Unio subtrapezius (junior). Phili. 

 Unio membranaceus. Phili. 



1 Turton's figure seems to me to be an elongate variety of littoralis, analogous to that which I described, in 

 error, under the name of incurvus. But Forbes and Hanley say that littoralis does not now exist in the waters of 

 Great Britain, and is only found there in the Pliocene formation, in a fossil state. If this be so, then Turton's 

 figure must be erroneously given. 



2 I have some doubts whether this should be considered more than a variety of circulus. I am not, however, 

 sure that it is not distinct. 



3 Although Mr. Say had published this shell in the Transylvania Journal, and in his Am. Conchology, he 

 omitted it altogether in his Synonymy. He inserted other species from the vicinity of New Orleans. 



4 I formerly placed this with the Anodontee, but D'Orbigny, who has seen the shell in its native waters, having 

 placed it among the Uniones, I follow him, never myself having seen the shell. The figure of Dr. Maton {Linn. 

 Trans., vol. s.) is without teeth, and the text says expressly "cardo edentulus." Notwithstanding this, I am in- 

 clined to believe that D'Orbigny is right, for the form of the shell is such as I have not seen in the Anodontee. 

 Not knowing what induced M. D'Orbigny to change Dr. Maton's name, I have restored it. 



(Since this note was published, M. D'Orbigny, in his Voy. Am. Mer., has come to a different conclusion as 

 regards Mytilus membranacea, Mat. He now thinks that my Anodonta lato-marginata is the same with mem- 

 branacea, but I do not think that Maton's figure can be referred to lato-marginata, even supposing the figure of 

 membranacea made by Maton to be from a young specimen. The outline is not the same, membranacea being much 

 more rotund, and the very great difference of solidity must have its influence in our decision ; lato-marginata being 

 one of the thickest of the Anodontee. M. D'Orbigny, in Mag. de Zool., 1835, gives Mya membranacea as a 

 synonym to Unio Matoniana, and says the teeth are thin; but he ought to have cited it as Mytilus, as Maton does 

 not give Mya membranacea, but Mytilus membranacea. M. D'Orbigny places it now among the Anodontee, and 

 restores Maton's specific name of membranacea, and considers my lato-marginata as a synonym. It does not 

 appear to me, from the description and figure, that they can be the same.) 



