220 kelliid.i:. 



middle, produced or wedge-like and rounded at the anterior 

 end : beaks broad, blunt, prominent, and contiguous ; they are 

 placed about two-fifths nearer to the posterior end : hinge-Vine 

 curved, occupying rather more than one-fourth of the circum- 

 ference : cartilage large, yellowish -horn colour, attached to the 

 shell below the hinge-plate and lodged on an oblique shelf: 

 hinge-plate very broad, thick, and strong: teeth, in the right 

 valve two triangular laterals with sharp points, the anterior of 

 which is a little more raised than the other ; in the left valve 

 similar laterals, besides a minute cardinal and erect tooth 

 directly below the beak ; the laterals in each valve lock into 

 corresponding grooves in the other : inside partially nacreous, 

 but otherwise of a dull hue ; margin plain : pallia! scar scarcely 

 visible, but evidently existing on account of the adhesion of 

 the mantle inside the front margin : muscular scars oval and 

 distinct. L. 0-85. B. 0-1. 



Var. pallida. Shell yellowish -white and nearly trans- 

 parent, without any tinge of purple or red. 



Habitat : Everywhere in crevices of rocks, inside the 

 empty cups of Bcdani and among the tufts of Lichina 

 pygmcea, near high-water mark, and at the roots or 

 footstalks of CoralYina officinalis and other seaweeds, 

 and on mussel-beds, between tide-marks ; sometimes it 

 is found at depths varying from 3 to 20 fathoms. The 

 variety is not uncommon. This species is a Coralline 

 Crag shell. Steenstrup has found it in Iceland, and 

 Lilljeborg at Grip in Upper Norway ; but I am not 

 aware of anv other northern locality. It is widely 

 diffused southwards from the north of France to the 

 Canary Isles, and throughout the Mediterranean. Spe- 

 cimens for which I am indebted to the kindness of 

 Mr; Cuming (so renowned for his unrivalled collection 

 of shells, as well as for the extent of his conchological 

 experience), and taken by him on the south-western coast 

 of America, cannot be distinguished from the European 

 species ; and Dr. Philip Carpenter is of opinion that a 

 species from the Gulf of California is the same as ours. 



