90 SCALARIID^E. 



tudinal ridges, 12 being on the last whorl, 11 on the penulti- 

 mate, and 10 on the next, after which they diminish in number; 

 these ridges are broader and foliaceous at the top of each whorl ; 

 they are not continuous throughout the spire, but are usually 

 disposed in alternate order, and some of them, at irregular 

 intervals, are double or multiple, so as to form broad and strong 

 varices ; the interstices of the ribs are finely and closely stri- 

 ated in a spiral direction : colour light yellowish-brown, with 

 3 purplish-brown or coifeecoloured bands on the body-whorl 

 and 2 on each of the other whorls ; of the 3 bands the upper 

 two are above the periphery and sometimes confluent, the third 

 (which is generally broader) encircling the base : spire tapering 

 gradually to a fine point : whorls 15-16, rounded, although 

 compressed, and increasing very gradually : suture well defined, 

 but not deep : mouth more round than oval, angulated above, 

 and much more so below : outer lip encircled or strengthened 

 by the last-formed ridge, having a slight sinus near the upper 

 part, and somewhat reflected : inner lip broad, extremely thick 

 at the base and lower angle of the mouth ; there is no umbi- 

 licus behind it: operculum dark-horncolour, having about 6 

 turns, rather concave, and strongly striated in the line of 

 growth ; it resembles that of a Littorina, but the nucleus is 

 more central. L. 1-75. B. 0-5. 



HABITAT : Coralline zone in Guernsey (Lukis) ; Devon 

 and Cornwall (Turton and others) ; Tenby (J. G. J.) ; 

 Laugharne, Carmarthenshire (Barlee, and Lindsay) ; 

 estuary of the Mersey (Collingwood) ; Scarborough 

 (Bean and Leckenby) ; Aberdeen (Macgillivray) ; Clyde 

 district (Forbes and others) ; co. Down (Thompson) ; 

 Dublin Bay (Turton and others); south of Ireland (Ball 

 and others) ; co. Galway (Barlee) . It is by no means 

 common. Dr. Turton states that "in many parts 

 of Ireland, but especially about Balbriggan, they are 

 found crawling among the rocks " ! In a fossil state 

 this species has been recorded from the Belfast deposit 

 by Hyndman and Grainger, under the name of S. Tre- 

 velyana ; Ireland, Ayr, and Bute (Smith) ; Nice (Risso) ; 

 Sicily (Philippi) . It inhabits the North Atlantic from 



