2 'A'NOMIA. BOWL-SHELL. 



1 . Aivjmia;Eph5ppkmv Twinkled Boicl-shelL 



Lister, pi. 204. f. 38 Pennant, pi. 65. upper fig. Da 

 Costa, pi. 11. f. 3 Linn. Tram.vi.pl 18. f. 11, 12 Dono- 

 van, pi. 26 Domtf Cert, pi. 11. f.3. 



Shell thin, more or less transparent, rather convex, 

 rounded, irregularly wrinkled and plaited, and often in- 

 dented on the margin ; the outside dirty white, or of a 

 brownish cast j inside perlaeeous ; beak small pointed, 

 curved, and reaching to the end of the margin : the flat 

 valve with an oblong rather oblique perforation close to 

 the hinge, which is generally cut off by the margin of the 

 upper valve, and often taking the impression of shells and 

 other substances to which it may be attached : diameter 

 hardly three inches. 



Variety A. Reversed, or with the convex valve perforated. 



Variety B. Thick, strong, somewhat orbicular, but a 

 little produced on one side, quite even round the circum- 

 ference and not wrinkled nor plaited ; the upper-valve a 

 little rugged on the outside, and scaly towards the margin :. 

 color dull white with a slight tinge of purple, and of a 

 most rich pearly lustre when the outer coat is removed : 

 beak reaching close to the margin, which is rather rounded ; 

 inside finely polished, of the most splendid perlaeeous 

 lustre, 'with a tinge of dark green towards the produced 

 side : lower valve a little concave, thin, transparent, per- 

 laeeous except round the margin of the aperture, which is 

 large oval and extending to the hinge : length two inches 

 and a quarter ; breadth two and a half. 



This most beautiful shell, by far exceeding the finest 

 pearls we have ever seen in the richness and splendor of 

 its iridescent gleams, was brought to us from Torbay in 

 the autumn of 1817. Beneath the cartilage impression 

 are two oblong cavities, about a quarter of an inch in length, 

 evidently the lodgement of pearls : and it is probable, that 

 ir the larger species of this family could be procured from 

 the deeps of the ocean, the most valuable pearls might be 

 obtained from them. Our knowledge of this shell being 

 confined to this single specimen, we can for the present 

 only consider it as a variety. 



Variety C. Of a triangular shape, appearing as if regu- 

 larly 



