24 eafinesqtie's 



fossil shells. They consist in 4 naked mollusca, of the genus Limax, 

 36 fluviatile univalve shells, 34 terrestrial univalve shells, 42 fluvia- 

 tile bivalve shells, and TO fossil bivalve shells. Such as— (*these are 

 fossils)— Helix, 4 species ; Planorbis, 2 ; Ancylus, 1 ; Mesomphix, 

 N. G. t. univ. 12 ; Trophodor, N. G. do. 10 ; Triodopsis, N. G. do. 

 2; Stenotoma, N. G. do. 1; Toxostoma, N. G. do. 1; Xolotrema, 

 N. G. do. 1; Aplodon, N. G. do. 1 ; Lymnula, 13; Pleurotoma, N. 

 G. fl. un. 12 ; Ellipstoma, N. G. do. 4 ; Bulimus, 1 ; Burystoma, N. 

 G. fl. un. 1 ; Notrema, N. G. do. 1 ; Ambloxis, N. G. do. 4 ; 

 *Voluta, 2; *Solarium, 2s *BelemniteS, 3;**Trochus, 3; *Ortho- 

 cera, 5 ; *Toxerites, N. G. un. 1 ; *Bndotoma, N. G. do. 1 ; 

 *Platinites, J^. G. do. 1 ; *Trigorima, N. G. do. 1 ; -Euomphales, 

 1 ; *PateUa, 2 ; *Melanites, 2 ; Mytilus, 1 ; Lepas, 1 ; Potamila, 

 N. G. fl. biv. 34 ; Truncilla, N. G.- do. 3 ; Stenodon, N. G. do, 3 ; 

 Pleuroxis, N. G. do.> 2 ; *Saconites, N. G. I ; *Gryphea, 5 ; *Ostrea, 

 2 ; *Terebratula, 24 ; *Productus, 15 ; *Spirifer, 2 ; *Tellina, 1 ; 

 *Goniclis, K G. biv. 2 ; *Cyphoxis, N. G. do. 5 ; *Megorima, N. 

 G. do. .4 ; *Oxisma, K G. do. 1 ; *Curvula, N. G. do. 3 ; *Apleu- 

 rotis, N. G. do. 2; *Pachosteon, N. G. do. 1. 



[356] 

 Description of a tiew Genus of Fluviatile Bivalve Shell, of the 

 family of Brachiopodes ; Notrema Fissubella ;, m a Letter to 

 Dr. 8. L. Mitchill, Prof, of Nat. Hist. &c., New Torh. 

 Dear Sir : 



There is a small family of bivalve shells, which have received the 

 name of Brachiopodes, distinguished by having tentacula. It con- 

 tained, in my Analysis of Nature and in Cuvier's Regne Animal, 

 only three genera, lingula, orbicula and terehratula, all maritime ; 

 this last, whicn is very numerous, particularly in fossil species, has 

 lately been divided by Sowerby, who has established the genera Pro- 

 ductus and Spirifer ; and I have added another fossil genus. 

 Apleurotis, distinguished from it by being elongated, obliquated, 

 and auriculated on one side only, in a memoir presented to the 

 Academy of National Sciences of Philadelphia. 



In my travels on the Ohio, I have ascertained another genus 

 belonging to that family, which is very similar to the genus Orbi- 

 . cula ; but it is fluviatile, and the larger or upper valve is perforated 

 in the middle as in Fissurella, and operculated. I have not seen 

 the living animal myself; but Mr. Audubon of Hendersonville, a 

 Zealous observer, has drawn it, and it appears to have a head with 



