Notes on Amenran .*/„/*. 



Art. XVI. Notes on the American Shells, figured in the 8up- 

 plement to the Index Testaceohgicus. By Jacob Green, M. D. 

 Professor of Chemistry in Jefferson Medical College, Philadel- 

 phia, Corresponding Member, 



Read June 7, 18S0. 



The object of the present communication is to correct some of 

 the inaccuracies which occur in the Supplement to the Index Tes- 

 taceologicus of W. Wood, Esquire, lately published in London. 

 On three or four of the plates which adorn this beautiful work, we 

 have a number of American shells accurately delineated, but on re- 

 ferring to the accompanying catalogue, for their names, these will 

 be found in almost every instance, to be incorrect or misapplied. 

 Plate 1st. 



In this plate, under the head Mya, we have figured 12 bivalves, 



all said to be inhabitants of the United States. 



Fig. 1. Is called Unio Rotunda— It is, we think, the U. Circu- 

 lus of Mr. Lea. This shell we saw labelled with the name, 

 U. Rotunda some years since in the cabinet of the British Mu- 

 seum. Mr. Lea's name, U. Circulus, must therefore be aban- 



Fig. 2. Is called Unio Oblongata. We never saw or heard of 



this species before. 

 Fig. 3. Unio Alatus— A bad representation. 

 Fig. 4. Unio Nasutus.— Very good. 



Fig. 5. This is called Unio Undulatus.— It certainly does not rep- 

 resent the U. Undulatus of Barnes— Mr. Lea, in his paper on 

 American Unios, says that this shell should be called the U. Pli- 

 catus of Le Sueur. Waving the objection that Le Sueur nev- 

 er described a shell, we repeat* that La Marck's name U. Pe- 

 ruvianus, has the priority, and therefore must be applied to it. 



Fig. 6. This is called Unio Gravis in one place, and U. Cariosus 

 in another ; the last name is probably right. 



Fig. 7. Is called Unio Rugulosa. It cannot be the U. Rugosus 

 of Barnes, which Mr. Lea, has improperly noticed as a variety 

 of U. Metanevra of Rarlnesque. 



Fig. 8. Is called Unio Obliquus. It is perhaps intended for U. 

 Obliqua of La Marck, or U. Scalenius, Raf. 



*See Contrib. Mac. Lyceum, to!, !. page 44. 



