M A E G A R I T A X A. 



69 



WIDE. 



"'Hildrettiana.' Lea. 



Unio Hildrethianus. Lea. 

 Al. amhigua? Say. 



*de]iiscens.^ Say. Lea. 



Unio dehiscens. Say. Desh. Han. 

 Unio oriens. Lea. 



OBOVATE. 



*Connasaugaensis. Lea. 

 *Spillmanii. - Lea. 



ARCUATE. 



*inargaritifera.^ Lin. Lea. Cooper.*" 

 Mya margaritifera. Lin. Miil. 



Born. Schrot. PennaJit. Don. 



Ghem. Knorr. Da Costa. Dill. 



Desh. Wood. Mat. Monta. 



Muhl. Nil. Schreib. Cuv. 



Rossm. Dup. Eat. Ghenu, Moq. 



crassissima. Klein. 



Margaritana fluviatilis.^ Schum. 

 Margaritana arctiata. Stimpson. 

 Margaritana {Unio) Mongolicus. 



Midd. 



f ARCUATE. 



Unio elongata. Lam. Midi. Bouil. 



Nils. Puton. Potier. Dup. 



Merm. Oras. 

 Unio sinuata. Stud. Pfeif. 

 Unio Soissyi. Mich. Desh. Oras. 

 Unio margaritiferus. Reiz. Speng. 



Pfeif. Cuv. Drap. Base. Turt. 



Oaertner.^ Menlie. Waard. Rossm. 



Dup. Bouil. Alder. Gras. Han. 

 Unio margaritifer. Oraells. Schrenk. 



Midd. 

 Unio rivalis. Zieg. 

 Unio GarolinianusJ Bosc. 

 Unio Dahuricus. Midd. Gerst. 

 Alas, margaritiferum. Flem. Brown. 



Macgil. 

 Alas, margaritiferus. Thompson. 



Forbes. 

 Alas, elongatus. Thompson. 

 Alas, arcuata. Bar. Gould. Adams. 



Migh. Linsl. Dehay. 

 Mya arcuata. Eat. 

 Alas.falcata. Gould. 

 Alas. Yubaensis. Trask. 



' In the previous editions, this was placed among the Uniones witli much hesitation. I now think it 

 gronps better with the Margaritanse. Its cardinal tooth is very much like M. Bonellii, and the callus of 

 the dorsal margin is sometimes, in both, so much thickened as to present an imperfect appearance of a 

 lateral tooth. Mr. Say's desci-iption of ambigua answers well to Hildrethiana., but I am not sure it is 

 the same, as he has given no figure of it. He seems to have abandoned it, as he does not insert it in his 

 Synonymy. Mr. Conrad also avoids the insertion of it in his Synoptical Table. 



^ Mr. Say, in his Synonymy., gives Mr. Rafinesque's name of lata precedence. Mr. Eaton sa,ys that 

 An. lata, Raf., is Sympliynota tenuissima, Lea. 



^ Klein describes this species under the name of crassissima, but with no generic term. This name 

 has been, by Ferussac and other zoologists, erroneously applied to the large Unio, common to the south 

 of Europe, which Retzius described as Unio crassus, and 1 have given it to Retzius. Klein's crassissima 

 is the true Margaritana margaritifera (3Iya margaritifera, Lin.), and his figure of it, PI. x. Tig. 4Y, is a 

 copj' of Lister's, Tab. 149, Fig. i. 



* Judge Cooper states, under the authority of Dr. Cooper, that the Indians east of Cascade Moun- 

 tains eat this species. 



'^ I adopt Schumacher's generic name because he has priorit}'; but I discard his specific name of 

 fluviatilis because he changed, without any reason, the long and well-established specific name of mar- 

 garitifera. 



" Fide Menke. 



' I have been, and am still, perplexed about this species of Bosc. M. Ferussac considers it the same 

 with Unio obesus (nobis), and I so stated it in my second edition. Recently, I have had access to Bosc's 

 description and figure (Hist. Nat. des Coquilles), which agree better with 3Iargaritana margaritifera 

 than any other species; and he refers to the figure of it in Ency. Metli. 

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