194 kelliid^:. 



that the shell gapes. It can be completely closed on all 

 sides at the will of the animal. A species (L. loripes), 

 half an inch long, found on the coast of Florida has 

 a singular habitat. According to Mr, Stimpson, the 

 discoverer, " it lives in sand or mud, on the flats, near 

 low-water mark, at the depth of a foot below the surface, 

 and generally occupies the holes of marine worms and 

 fossorial Crustacea." This might warrant a supposition 

 that the animal of Lepton is predacious. 



Three species of Lepton are enumerated in Dr. Philip 

 Carpenter's list of mollusca from the west coast of 

 North America. The genus Scintilla of Deshayes ap- 

 pears to be closely allied to the present genus. 



A. Shell pit-marked. 

 1. Lepton squamo'sum *, Montagu. 



Sokn squamosus, Mont. Test. Brit. i. p. 565. L. squamosum, F. & H. ii. 

 p. 98, pi. xxxvi. f. 8, 9, and (animal) pi. O. f. 6. 



Body clear white : mantle very large, having its margins 

 flexuous and often puckered into two or three folds; the 

 margins extend considerably beyond the shell, and from them 

 springs, on each side of the ventral range in the middle, a row 

 of 25 rather long, slender and pointed milk-white tentacular 

 filaments ; the pallia! margin has also at its sides 40 long, 

 strong, close-set, blunt, frosty-white cirri of different lengths, 

 one of these last filaments being much larger and longer than 

 the others, and resembling one of the tentacles of a Gastero- 

 pod: excurrent tube short : foot bluish- white, and transparent, 

 with a broad streak of intense snow-white running down the 

 middle, and a still more conspicuous flake at the anterior end ; 

 it is fixed to the centre of the body by a moderately long 

 pedicle. (Clark.) 



Shell roundish-oval, with a tendency to a square outline 

 in consequence of the front margin being nearly straight and 

 of the hinge-line being unusually broad; it is very much 



* Scaly. 



