SYNOPSIS OF 



best place for the Symphynote shells would be a division of 

 the subgenera into Symphynote and Non-Symphynote. 



r 



•I— I 



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1. Subgenus Unio, 



Having a cardinal and lateral tooth. 



2. Subgenus Margaritana, 



Having one tooth (cardinal). 



3. Subgenus Dipsas, 



Having a linear tooth under the 

 dorsal margin. 



4. Subgenus Anodonta, 



Having no teeth. 



' Symphynote — Unio ala- 

 tus,^ &c. 

 Non-Symphynote — 

 Unio pictorum,^^ &c. 



Symphynote — Alas. 



complanata,*^ &c. 

 Non-Symphynote — 



Alas, undulata,*^ &c. 



Symphynote — Dipsas 

 plicatus.*^ 



Symphynote — Sym. 



magnifica/ &c. 

 Non-Symphynote — 



An. fluviatiliSjS &c. 





5. Subgenus Pleiodon,* C tvt o \. ,. t> 

 =• ' \ Non-Symphynote — r. 



Having the dorsal line granulate, j Macmurtnei. 



Note. — It should be remarked here that this ge- 

 nus is not used on Lamarck's character, " charniere 

 tuberculeuse dans sa longueur," but with that of the 

 animal's having tubes, otherwise it must go with the 

 subgenus Anodonta. I believe that the same spe- 

 cies may be observed with and without a tubercu- 

 lated hinge. 



* A new genus proposed by Mr. Conrad for a beautiful shell from Liberia, 

 a Of Say. b Of Lamarck. ^ Of Barnes. d Of Say. 



6 Of Leach. Only two species yet known, this and <S. discoidea, Lea. 

 f Lea. g Mytilus furiatilis, Sol. Dill. &c. A71. cataracta, Say. 



h Conrad. In the text this name is J[Iacmurtrei : that of the plate is most 

 correct. 



