( 263 ) 



A Descriptive Catalogue of the GASTER0P0D0U8 JWLLVSCA 

 of Berwickshire. By George Johnstox, M.D., F.E.C.S.E. 



Part TI. 



Order— PECTINIBEANCHIATA. 



Division— ASI PHONOBE ANCHI AT A. 



Animal shelled, trachelipode, rarely gasteropode ; the shell spiral, 

 sometimes patelliform, with the margin of the aperture entire or 

 continuous all round. — The genera are dioecious, in general 

 phytophagous, and, with a few exceptions, inhabitants of the sea- 

 shore. 



7. Scalaria. Lamarck. 



Shell turreted, the whorls crossed with elevated subacute ribs ; 

 aperture round, the margin continuous and reflected, the lower part on 

 the side of the pillar formed into a sort of obsolete canal ; operculum 

 horny, spiral. — Zoophagoux. 



1 . S. Trevelyana, shell yellowish-brown or white, with ten rounded 

 whorls gradually tapered to a point, crossed by about fifteen thick 

 plain ribs, interrupted by a separating line, the intermediate 

 spaces smooth ; aperture white, round. Height -roths ; diameter 

 of base -^^ths. Leach in Eaine's Durham, p. 174. 



Sah. Berwick Bay, rare : Holy Island. 



I have seen only worn specimens, so that the natural colour remains to be 

 determined. The shell is strong, and without any gloss in my specimens, 

 and the ribs are obtuse and enlarged at the suture, where, instead of 

 running in an uninterrupted line, they are a little bent, and fall into the 

 intermediate spaces. The species is very like, and nearly allied to Sc. 

 Turtoni, but differs from it in being smaller, and in having more numeroua 

 ribs. 



8. Trochus. Linn^us. 



Shell conical, the body-whorl angulated so as to make a flattened 

 base, on which the shell rests when set on a plane surface ; aperture 

 transversely depressed, subquadrate, the margins disjoined, silvered 

 interiorly; pillar arched: "operculum horny, circular, spiral, with 

 numerous close-set volutions, and having the spiral line external." — 

 Sowerhy. 



* Base imperforate. 



1. T. zizyphinus, shell conical, yellowish-brown or flesh-colour, 

 spirally ridged, the ridges flat and smooth ; whorls eight, flat, 



