48 LITTORINID^E. 



on the under surfaces of stones laid bare at low water 

 of spring tides. It swims, like its congeners, with the 

 sole of the foot uppermost. 



It is possibly the Turbo scriptus of Adams, and un- 

 questionably R. pulchra of Johnston, R. tristriata of 

 Thompson, and R. subsulcata of Philippi. R. semistriata 

 of the last named author, from the Red Sea, appears to 

 be different from our species. 



25. R. cingil'lus *, Montagu. 



Turbo cingillus, Mont. Test. Br. p. 328, t. 12. f. 7. B. cingillus, F. & H. 

 iii. p. \ 22, pi. lxxix. f. 9, 10, and (animal) pi. J J. f. 4. 



Body pale -yellowish -white or milk-white; snout semi- 

 transparent : tentacles long, nearly cylindrical, flexible, with 

 somewhat bulbous tips : eyes black and conspicuous, sometimes 

 on whitish tubercles : foot narrow, bat proportionally short, 

 squarish in front and bluntly pointed behind ; caudal cirrus 

 not observed. 



Shell conic-oblong, rather solid, semitransparent, and 

 somewhat glossy : sculpture, on the body-whorl from 12 to 20 

 slight spiral ridges, which are sharp and distinct below the 

 periphery, but more or less obsolete above it ; these ridges are 

 scarcely perceptible on the other whorls ; they are crossed by 

 numerous fine striae in the line of growth, causing an imperfect 

 decussation ; the last whorl is slightly angulated : colour buff 

 or yellowish-white, with two chocolate or reddish-brown bands 

 on the last whorl, and one on each of the upper whorls, besides 

 part of a second band above the suture ; there is also a third, 

 shorter band or streak at the base ; and occasionally, when the 

 bands are narrow, a fourth may be seen between the lower 

 band and the basal streak : spire long and gradually tapering, 

 with a -blunt tip : ivhorls 6-7, flattened, the last occupying 

 about two -fifths of the spire : suture distinct and slightly 

 channelled : mouth rather small : outer lip sharp : inner lip 

 forming a glaze on the pillar, and united with the upper lip at 

 the outer angle : operculum horncolour, marked with diverging 

 lines of growth. L. 0-175. B. 0-085. 



Var. rupestris. Creamcolour or milk-white, and bandless. 

 R. rupestris, Forbes in Ann. N. H. v. p. 107, pi. 2. f. 13. 



* For cingillum, a small girdle. 



