82 KELLIADiE. 



riorly, the front being so pale as, in some specimens, al- 

 most to be devoid of colouring- matter ; the beaks are dark 

 purple. The valves are moderately convex, and rounded 

 at both ends, the termination of the posterior side, — which 

 is much produced, — more obtusely and broadly so ; the ex- 

 tremity of the anterior side, — which is both narrow and 

 small, at most occupying one-fourth of the length of the 

 shell, and a very much smaller proportion of its area, — sim- 

 ply and regularly so. The ventral margin is subarcuated, 

 and both dorsal lines are decidedly convex, the front one 

 declines strongly, the hinder one scarcely slopes at all. 

 The umbones appear oblique, and when viewed in front 

 are decidedly prominent, they being raised on that side con- 

 siderably above the dorsal line. The beaks themselves are 

 blunt, and there is no defined lunule in front of them. The 

 internal colouring resembles the external, the margin is 

 plain, and the pallial impression, as far as can be ascer- 

 tained, is simple and not siuuated. The cardinal edge is 

 very narrow, only jutting out just at the shorter side, to 

 which portion of it the dentition is confined. The extreme 

 minuteness of the teeth almost baffles one's eyesight, even 

 when aided by the most powerful lens, and from the lesser 

 size of our British examples, the dentition does not aj^pear 

 so clearly developed as in the northern exotic ones.* 



We are unable to perceive any lateral teeth, although 

 there is a very slight elevation of the hinge-margin at the 



* Loven's description of the hinge stands thus :— " Cardo valvar destrae fossa 

 lunulari parum profunda, dente lunulari subtrigono, valido, fossa cardinal! an- 

 gusta, profunda, subtrigona, dente cardinali fere sub medio uiubone sito, lunulari 

 pauUum minore, rotundato ; valvar sinistrse dente lunulari minuto, antrorsum 

 obliquo, fossa lunulari magna, trigona, dente cardinali valido, fossa cardinali 

 magna, satis profunda ; dentes laterales parum prominuli, longitudinales : im- 

 pressio muscularis antica duplex, superior minuta, inferior ovalis, verticalis, 

 posterior ovalis, supeme emarginata ; impressio palliaris vix discernenda integra 

 videtur." — Index Moll. Scand. p. 43. 



