270 



POPULAR CONCHOLOGY. 



in others, interrupting the hinge margin ; muscular scars, 

 suborbicular ; pallial sinus entire. Animal suborbicular, 

 its mantle much closed, furnished posteriorly with a single 

 very short siphonal (anal) tube, and anteriorly prolonged 

 into a canal, or hyaline tube, of considerable dimensions, 

 the margins of which are either united, so that a separate 

 orifice is formed, or open, so as to be continuous with the 

 pedal slit ; foot ligulate, furnished with a byssal groove ; 

 branchial leaflets free; lateral palpi triangular.* — Several 

 species; also fossil. 



Mr. Alder says that K. suborbicularis which is found on 

 the English shores, produces a very delicate thread, and 

 suspends itself freely by a single, almost inconspicuous 

 fibre, strengthened by a double attachment at the top. 

 It lives in crevices of rocks, or sea-weed roots. 



Lasea. Leach. (Cycladina Cantraine ; Poronia Re- 

 cluz.) — Shell almost entirely similar to Kellia, but 

 smaller, mostly of a reddish colour, and the inner ligament 

 on a projecting process, and not immediately under the 

 bosses. Animal with a byssus according to Loven. — 

 Several species. 



Philippi says that the type of this genus is the small shell 

 Cardium rubrum of Montague, found on the British shore. 



Lepton. Turton. — Shell flat, rarely orbicular, equi- 

 valve, inequilateral, a little open at the sides ; 

 hinge of one valve with a single tooth, and 

 a transverse linear lateral one on each side ; 

 the other valve has a cavity in the middle 

 and a transverse deeply cloven lateral tooth 

 on each side, the segments of which divari- 

 cate from the boss ; pallial impression simple. 

 Animal compressed, mantle freely open in 



* Forbes's British Moll. 



