260 



M. with a very rough, (trong, angulated (lieM, of a 

 dirty white, or brownilh colour : with [even or eight ru- 

 gofefpires much produced, and terminating in a fine point: 

 on each vohnion are fix or feven rugged, prominent, lon- 

 gitudinal ribs, crofi^ed by tranfverfe, elevated firing: the 

 whole fliell imbricated with finall concave, or arched fcales, 

 very confpicuous on the body : aperture oval ; canal tu- 

 bular; outer lip thickened by a rib, inner margin denta- 

 ted; pillar lip fmooih glofiy-white. Length an inch and 

 three-quarters, and nearly an inch wide. 



In very young fpecimens the gutter or canal is open, and 

 the whole fiiell is covered with elevated points, which be- 

 ing fometimes worn, gives it a pretty cancellated appear- 

 ance, and in this ftate may readily be miftaken for a diftinft 

 fpecies. 



This is not uncommon on many of our fliores ; but the 

 finefl: and mod perFeft fpecimens are t;tkcn by dredging; 

 fometimes a pretty variety, mottled or zoned with ferrugi- 

 nous and white. 



6. 

 PuRPURt-us. M. with a very rugofc fliell, of a dark purple colour. 



Tab. 9.f. 2. with fometimes a few fpots or blotches of white: voluti- 

 ons nine or ten, rounded, and tapering to an extremely 

 fine, fliarp point, furniflied with nineteen or twenty ribs, 

 running a little oblique to the right ; croffed by numerous 

 {harp, elevated ridges, which rife into angles upon the ri' s, 



makinji 



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