92 KETJJAD7E. 



Jx. Ball, and E. F). Ranging to Bergen, in Norway, north- 

 wards, and to the Mediterranean, southwards. It is a crag 

 fossil. 



K. NiTiDA, Turton. 



Minute, white ; not more than one primary tooth in either valve. 



Plate XXXVI. fig. 3, 4. 



Lopton niiidum, Turt. Dithyra Brit. p. 63. — Fi,em. Brit. Anim. p. 429. — Brit. 

 Marine Conch, p. 49. — Macgilliv. Moll, Aberd. p. 278. — 

 Brown, 111. Conch. G. B. p. HI. 



The dentition of this shell, which has a primary tooth 

 in each valve, by no means agreeing with the characters 

 assigned to the hinge of Lepton by Turton (it is, more- 

 over, closed at the sides, and not a " little open'"), we 

 are compelled to remove it from that genus to the pre- 

 sent, of which we regard it as a somewhat aberrant 

 species. 



From its rare occurrence, and its very insufficient de- 

 scription in the pages of the " Conchylia Dithyra Britan- 

 nica," it has generally been conjectured to be the young of 

 the Lepton squamosum, to the fry of which, except in 

 shape, it bears but little resemblance, the characteristic 

 punctures being clearly manifest in all stages of that 

 species : it is far more liable to be confounded with the 

 young of K. suborbicularis, from which, however, its more 

 compressed shape and solitary apical tooth, suffice to dis- 

 tinguish it. Its white, thin, and subdiaphanous valves, 

 which, when fresh, are covered with a shining ochraceous 

 epidermis (variable in depth of tint, being occasionally 

 very pale), reflecting a little the prismatic colours, are 

 much depressed, excepting upon the umbonal region : the 

 compression is nearly equal on both sides. The shape is 



