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A Descriptive Catalogue of the GASTEROPODOUS MOLLUSCA 

 of Berwickshire. By GEORGE JOHNSTON, M.D., F.R.C.S.E. 



PART II. 



ORKR PECTINIBRANCHIATA. 

 Dmaiow ASIPHONOBRANCHIATA. 



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

 sometimes patelliform, with the margin of the aperture entire or 

 continuous all round. The genera are dioecious, in general phy- 

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

 shore. 



7. SCALARIA. LAMARCK. 



Shell turreted, the whorls crossed with elevated subacute ribs ; aper- 

 ture 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. Zoophagous* 



1. S. Trevelyana, shell yellowish-brown er 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 ^ths ; diameter of 

 base y' 5 ths. Leach in Raine's Durham, p. 174. 



Hob. 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 speci- 

 mens, 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 t but differs from it in being smaller, and in having more nu- 

 merous ribs. 



8. TROCHUS. LINNJEUS. 



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 in- 

 teriorly ; pillar arched : " operculum horny, circular, spiral, with nu- 

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

 Sowerby. 



* Base imperforate. 



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

 rally ridged, the ridges flat and smooth ; whorls eight, flat, sepa- 

 rated by a smooth belt regularly spotted with pink ; apex acute, 



