GASTEEOPODA. 263 



Family IX. — Tuebintd^. 



Shell spiral, turbinated or pjT,"amidal, nacreous inside ; oper- 

 culum calcareous and pauci-spii'al, or horny and multi-spiral. 



Animal with, a short muzzle ; eyes pedunculated at the outer 

 bases of the long and slender tentacles ; head and sides orna- 

 mented with fringed lobes and tentacular filaments {cirri) ; 

 branchial plume single ; lingual ribbon long and linear, chiefly 

 contained in the visceral cayity ; median teeth broad ; laterals 

 5, denticulated; uncini very numerous (sometimes nearly 100), 

 Blender, with hooked points (Fig. 15, A). 



Marine, feeding on sea-weeds {algce). 



The shells of nearly all the turbinidge are brilliantly pearly 

 when the epidermis and outer layer of shell are removed ; many 

 of them are used in this state for ornamental purposes. 



TuEBO, L. Top-shell. 



Etymology, tiirho, a whipping-top. 



Synonyms, Batillus, Marmorostoma, Callopoma, &c. — Gray. 



Type, T. marmoratus. PI. X., Fig. 2. 



Shell turbinated, solid ; whorls convex, often grooved or 

 tuberculated ; aperture large, rounded, slightly produced in 

 front ; operculum shelly and solid, callous outside, and smooth, 

 or variously grooved and mammillated, internally horny and 

 pauci-spiral. In T. sarmaticus the exterior of the operculum is 

 botryoidal, like some of the tufaceous deposits of petrifying 

 wells. 



Animal with pectinated head-lobes. 



Distribution, 60 species. Tropical seas, West Indies, Medi- 

 terranean, C^.pe, India, China, Australia, New Zealand, Pacific, 

 Peru. 



Fossil, 360 species (including littorina) L. Silurian — . 

 Universal. 



Phasiai^ella, Lam. Pheasant-shell. 



Synonyms, Eutropia (Humphrey), Gray. Tricolea, Eisso. 



Type, P. australis. PI. X., Fig. 3. 



Shell elongated, polished, richly coloured; whorls convex; 

 aperture oval, not pearly ; inner lip callous, outer thin ; oper- 

 culum shelly, callous outside, sub-spiral inside. 



Animal with long ciliated tentacles ; head-lobes pectinated, 

 wanting in the minute species; neck-lobes fringed; sides 

 ornamented with three cirri; branchial plume long, partly 

 free ; foot rounded in front, pointed behind ; its sides moved 

 alternately in walking ; lingual teeth even-edged ; laterals 5, 



