RISSOA. 47 



not so long as in many other species, grooved in the centre above, 

 and deeply cloven at the extremity : tentacles cylindrical but 

 somewhat compressed, rather long, and covered with close-set 

 cilia : eyes on scarcely raised tubercles : foot squarish in front, 

 with slightly angular corners, and tapering behind to a blunt 

 point : appendage tricuspid and short, placed over the tail but 

 never projecting beyond it. 



Shell conic-oval, rather solid, semitransparent, and some- 

 what glossy : sculpture, on the body- whorl below the suture 

 about half a dozen slight spiral striae, of which the upper two 

 close to the suture are much stronger than the rest, and about 

 a dozen similar and distinct striae below the periphery, the 

 intermediate space being faintly also striated or frequently 

 quite smooth ; the other whorls exhibit the subsutural striae 

 only : colour pale yellowish-white, with a row of reddish-brown 

 short and broad longitudinal streaks or blotches on the upper 

 part of each whorl, and a second row of smaller and narrower 

 streaks on the lower part, which last are often interrupted or 

 broken ; the other whorls are seldom marked in this way : 

 spire rather short but pointed, with a blunt tip : ivhorls 6, 

 rounded but not convex, the last occupying nearly two-thirds 

 of the spire : suture slight, encircled by the uppermost and 

 strongest stria of each whorl: mouth open, though not expanded: 

 outer lip sharp : inner lip reflected on the pillar and base, 

 united above with the outer lip : operculum yellowish, and thin, 

 slightly striated. L. 0-01. B. 0-065. 



Yar. pura. White and spotless. 



Habitat : Littoral and laminarian zones, in England, 

 Wales, Ireland, and Scotland as far north as the outer 

 Hebrides (J. G. J.), Aberdeenshire (Dawson), Moray 

 Firth (Gordon), and Shetland (Barlee). The variety is 

 equally diffused, but more common in Guernsey than 

 elsewhere. Lilljeborg found this species in Norway, 

 and it occurs in the Cattegat ; but southwards it becomes 

 more frequent, both on the eastern coasts of the North 

 Atlantic and in the Mediterranean; Adriatic (von 

 Schrockinger) ; Algeria (Weinkauff) . 



This pretty little mollusk, which Clark called " a 

 bashaw with three tails/' congregates in family groups 



