2 14 S^^dl Life 



bands are not continuous as in aS'. turtonct', but broken 

 into short streaks or mottling. Whorls about 15, 

 separated from each other. Operculum dark brown. 

 It attains a length of nearly 2 inches, and its habitat 

 is similar to that of >S^. turtonce. 



Trevelyan's Wentletrap (S. trevelyana) is fawn 

 coloured, thinner than in S. communis, the white 

 ridges connected as in that species, but narrower and 

 more flattened, with a short spur on the upper part ; 

 there are 14 ridges across the lowest of the 14 or 

 15 whorls, which are not separated. Operculum 

 pale brown. The shell seldom exceeds 1 inch in 

 length. A deep-water species — 15 to 100 fathoms. 

 The Small Wentletrap (>S'. clathratiUd) is small, semi- 

 transparent, white, with thin ribs of regular size. 

 There are only 12 or 13 whorls, and the lowest of 

 these bears 18 ridges. Operculum yellow-brown. 

 Length about half an inch. It occurs sparingly in 

 the coralline zone all round our islands. 



The Aclis-shells (Aclis) are much like those of 

 Scalaria, but without the transverse ridges on the 

 whorls. The mouth of the shell is oval and slightly 

 expanded, the outer lips thickened. The animal is 

 slender, with a long retractile proboscis, long tentacles 

 with the e3^es at their base, and the square-fronted 

 foot pushed out in front of the head in w^alking. 

 There are only two native species. The 

 Glossy Aclis (A. supra-nitida) is about a 

 quarter of an inch in length, white, with or 

 Glossy without spiral ridgfcs, and the oval mouth 



Aclis-shell . ,. . *• 1 -, n^, T . 1 



inclmmg strongly to roundness. The Little 

 Aclis {A. ascaris) is only about one-tenth of an inch 

 in length. It is more slender than the Glossy Aclis, 



