168 POPULAll BRITISH CONCHOLOGY. 



their base^ and a small rounded head ; the mantle is entirely 

 enclosed and covered by the thin shell ; and the foot is nar- 

 row, slender, very much produced beyond the head in front, 

 and scarcely extended at all behind. 



S. Turtoni, the only species found in Great Britain, has a 

 pretty little globular transparent shell, with a style-like apex. 

 Of this 8tylifef Mr. Alder says, in his ^Catalogue of the Mol- 

 lusca of Northumberland:^ — " We lately obtained a specimen 

 of this species alive on the spines of an Ecldnus at Culler- 

 coats, but rather injured, and in a very sickly state. We 

 placed it in a glass of fresh sea-water, hoping that it might 

 recover and display itself more distinctly ; but in this we 

 were disappointed, as it soon died, and, being left unlooked 

 at for a while, had partially decayed. The animal was 

 white, had a rather large foot, without operculum, and a 

 rounded head, with two cylindrical tentacles and minute 

 eyes at the base. No portion of the shell was covered by 

 the fleshy parts, but we are not prepared to say that, in a 

 state of vigour, the animal has not the power of extending 

 some part of the mantle or foot over it."*^ 



The last observation does not agree with Mr. Broderip's 

 account of the foreign species, who describes a sack -like 

 mantle enveloping a large part of the last whorl of the shell. 



