7I| CONCHYL[A— l>yT/ir/?^. 25. 



In size and form it exactly resembles the Goodallia triangula- 

 ris, among wliich it has doubtless been overlooked, but presents 

 the same differences as are observed between the Crassina sulcata 

 and Crassina Scotia, the margin being thinner and without the 

 least appearance of crenulations. 



25. SOLEN—LINNE. 



Testa Iransversim lineari-producta, tequivahns, ineequilatera- 

 lis, laterihus hiantihus. Cardo subtenninalis, umbonibus 

 obsoletis, dentibus numero et forma variis : lateralibtis nullis, 

 Ligamentum externum. 



Shell transversely produced and linear, equivalve, inequilateral, 

 open at the sides. Hinge near one end, with the beaks ob- 

 scure, and the teeth varying in number and shape : lateral 

 teeth none. Lisrament external. 



We have confined this genus to those of the Linnean family 

 of the Solen which have a linear and elongated form, as affording 

 a more simple and definite discrimination. 



The processes which extend along the cartilage edge of most of 

 them, can hardly be considered as lateral teeth, being attached in 

 a rib-like manner to the valves. 



