]14 



POPULAR CONCHOLOG1. 



on prominences; proboscis retractile, mouth armed with 

 jaws, and a denticulated tongue, armed with a single 

 series of broad, hooked, serrated central teeth, flanked on 

 each side by a triple series of laterals, of which the two 

 outer rows are simple and even edged, and the inner ones 

 broad, hooked, and serrated ; mantle ample, thick, more 

 or less reflected on the shell all round.* No operculum. 

 — 4 species ; also fossil. 



Inhabiting rocks in the seas of Britain, and other 

 northern countries. 



Trichotropis. Brod. and Sow. — Shell turbinated, 

 thin ; spire rather raised, and the 

 whorls keeled ; umbilicus large ; 

 aperture ovate ; the columella lip 

 arched, ending in a point, the 

 outer thin and sharp; the whole 

 shell covered with a horny epider- 

 mis, which extends into a row of 

 fine bristles on the keel ; the 

 horny operculum has the nucleus Trichotropis ucdnmta. 

 at the side. Animal with a short 



broad head, flanked by subulate tentacles, set wide apart, 

 bearing the eyes at the extremities of their thickened 

 lower halves; mouth inferior; proboscis long, retractile; 

 tongue with a single series of hooked and serrated central 

 denticles, flanked by three rows of curved laterals on 

 each side, of which the innermost only are serrated; 

 siphon scarcely exserted, distinct ; margins of mantle 

 simple, not reflected; foot broad, quadrate in front, rounded, 

 but not produced behind.f — 10 (?) species; also fossil. 



Very few specimens of this remarkable shell have been 

 found. One, with its inhabitant, was brought from the 



* Forbes's British Moll. f Ibid. 



