Notes on American Shells. 135 



Fig. 9. Is called Caslalia Ambigua. No species of Castalia has 

 been discovered in the United States— the only one seen by La 

 Marck was the C. Ambigua in the cabinet of the Marquis De 

 Dree. The genus Castalia however should no doubt be joined 

 to that of Unio. 



Fig. 10. Is called Unio Rigida. We arc wholly ignorant of this 



Fig. 11. Is the Unio Pra>longus of Barnes. La Marck's name, 



U. Rectus, has the priority. 

 Fig. 12. Is called Hyria Angulata. This shell is not, we think, 



a native of the United States. The figure looks something like 



one of the varieties of the U. Peruvianus. 



Plate ith. 



Fig. 26. This shell is called Strombus Noveboracenais, and is 

 said to be found in the harbor of New-York. It was new to us 

 —perhaps it is intended for the Nassa Obsoleta of Mr. Say. 

 Plate 7th. 



Fig. 11. This is rightly called Helix Tridentata— we have seen it 

 however more than three times the dimensions of the one figured, 



which is said to be of the natural size. 

 Pig. 12. This is named Helix Angulata. It is the Planorbis Bi- 



Fig. 13. This is 7 named Paludina Suhcarinatus. It is the Pal. 

 Dissimilis of Say. 



Fig. 14. This is called, as we are glad to find, Helix Septemvolva, 

 and not by the ill devised and unnecessary generic name, Poly- 

 gyra, proposed * " w. 



Fig. 15. This is name i Ueiix Monodon. It is the II. Fraterna 

 of Say — whether this last name has priority we cannot deter- 

 mine, as Mr. Wood docs not refer to his author. 



Fig. 16. This is named Helix Fraterna. It is the Helix Hirsuta 

 of Say. 



Fig. 17. This is named Paludina Discisa. It is Paludina Subca- 



Fig. 18. Thi Jis named Paludina Dissimilis. It is Paludina Dis- 



Fig. 19. This is named Paludina Yirginea. It is the Melania 



All the shells ^gured on Plate 7th, we are informed by Mr. 

 Wood in the preface to his interesting work, have been named from 



