

6 VELUTINID^. 



pears rather depressed as it lies upon the aperture ; the surface is 

 covered with a chalky incrustation, deposited by the animal, appar- 

 ently instead of an epidermis ; it is white, or flesh-colored, and gen- 

 erally with numerous zones of brown, of various widths ; 

 Fig- 606. -^yjjfji^ ti^jg ig removed, the shell is left pellucid ; aperture 

 ovate, ample, nearly the whole length of the shell, more 

 than double the size of the body of the shell ; outer lip 

 ^ _ ^ sharp and spreading ; inner lip sharp-edged, but margined 

 by a flattened, crescent-shaped, white, channelled space ; 

 the sharp edge is lost as it revolves within the shell, and a thin 

 plate of enamel covers the space between it and the junction of 

 the outer lip. Length, nine twentieths of an inch ; breadth, thir- 

 teen fortieths of an inch. 



Specimens have been found on Chelsea Beach, but are most eas- 

 ily obtained from fishes. Davis Straits, 66'^ 80' ; Halifax Harbor, 

 Banks ( Willis} ; Eastport, twenty fathoms ( Cooper) ; fossil, Mon- 

 treal (^Dawsoii). 



It is readily distinguished from the preceding by its more solid 

 structure, its flattened form, its expanded aperture, the flattening 

 of the left lip, and the peculiarity of the surface. Mr. Sowerby sent 

 a specimen from a raised beach on the Frith of Clyde, labelled 

 " Galericidum undatum, Brown," which is partly fossilized, but 

 bears a very close resemblance to our shell. The most marked dif- 

 ferences in the shell I received are, the greater breadth and excava- 

 tion of the flattened lip, and a more irregular exterior, which, from 

 the name it bears, I suppose to be constant. It may also be the 

 shell figured in Brown's " Conchology of Great Britain," as Galeri- 

 cidum ovatum, but nowhere described. The peculiar coating of the 

 shell adheres very closely, and might not be detected except by ac- 

 cident. Perhaps it does not always exist ; but in the striped speci- 

 mens it will always be found. I should think that specimens en- 

 tirely white, or flesh-colored, are as often found as the zoned ones. 

 In one fish, caught off Cape Ann, I found about a dozen very large 

 and beautiful specimens. 



Genus LA 1^1 ELL ARIA, Montagtt. 1815. 



Shell ear-shaped, aperture ample, spire small and depressed, 

 pillar spiral. 



