CONCHYLIA— l>/T//Fi2J. 18. 55 



Shell the eighth of an inch long, and a quarter of an iiicli broad, 

 convex, opake, transversely oval, obliquely truncate at the an- 

 terior e)ul, covered with a glossy Avliite skin under which it is 

 chalky white, irregularly striate transversely; beaks prominent, 

 close to the larger side which is abrupt; inside glossy white: 

 hinge with strong conic teeth, one in each valve penetrating into 

 a cavity of the opposite valve. 



Whether this be the shell mentioned by Montagu, as having 

 been taken among corallines, his short description will hardly 

 allow us to determine. Our specimens were taken from the in- 

 side of stones dredged in Torbay, varying a little in the outline, 

 but all fpreserving their strict generic character. They have 

 not however the purple tinge, probably in consequence of their 

 internal habitation and want of light: or it is possible that an 

 undiscovered species still remains. 



18. ERYILIA—Tl RTON. 



Testa ovata, (pquiimlvis, inaqiiilatctaUs, clmisa. Cardo dente 

 unico erecto inter duos mmutos vulva: altenus ])enetra}ite : 

 l(dcr(dihiis nidlis. JJgamentnm internum. 



Shell oval, ccpiivalve, inequilateral, closed. Hingo with a single 

 erect tooth closing between two small divergent ones in the 

 opposite valve: lateral teeth none. Ligament internal. 



