lANTHINA. 551 



body appears subject to much variation, the former being 

 much more elevated in fine Mediterranean examples than 

 in our more stunted native ones, in which latter the turns 

 of the spire are mostly depressed and rather short. The 

 suture, which is distinct but simple, and never canalicu- 

 lated, is generally succeeded at a little distance, especially 

 upon the last whorl, by an indentation that runs parallel 

 to it, and which produces the effect of margination. The 

 body, which is very ample, but whose expansion is in a 

 transverse and not a longitudinal direction, is more rounded 

 above than below, and is rather bluntly angulated at its 

 circumference. The aperture is subtrapeziform, and, at 

 the least, as wide as it is long ; it occupies fully four- 

 sevenths of the basal diameter, and ranges in length from 

 about five-sevenths to only half of the entire length of the 

 shell ; the younger the shell, the greater, in general, is 

 the proportion occupied by it. The medial sinuation of 

 the outer lip, whose outline is more arcuated posteriorly 

 than in front, and which meets the pillar at a right angle, 

 and the body at an obtuse angle, is very gradual, but of 

 considerable extent. The general inclination of the pillar, 

 which is about half the height of the shell and a little 

 wavy, is nearly straight ; its reflection wholly or partially 

 conceals any umbilical chink : in most native specimens 

 it is dark violet. The individuals mentioned by Brown 

 as taken in Ireland measured an inch by an inch and a 

 quarter, and hence were equal in dimensions to the fine 

 Mediterranean examples ; those which we have ourselves 

 met with, chiefly from the Welsh coast, had not attained 

 to more than half this size. 



The animal is white, tinged often strongly with purple. 

 The head is muzzle-shaped, thick, and rather long, with 

 somewhat obtuse tentacles and cylindrical sustentacles. 



