304 turbinid^. 



Family TURBINID^. 



Shell spiral, turbinated, nacreous inside. Operculum calca- 

 reous, paucispiral. 



Animal. Tongue elongate, median teeth broad, laterals five, 

 denticulated, uncini very numerous, slender, with hooked points 

 (xii, 47). Head proboscidiform ; tentacles subulate, sometimes 

 ciliated ; eyes on free peduncles at their outer bases ; two 

 more or less developed head-lobes between the tentacles. Gill 

 single, long and linear. Sides of the foot with a large neck- 

 lappet near the eye-peduncle, continuous with a conspicuous 

 side-membi*ane, bearing on its free margin from three to five 

 tapering filaments ; operculigerous lobe often ornamented with 

 cirri. Littoral and herbivorous, characterized by the fringed 

 lobes and tentacular cirri of the head and sides, their peduncu- 

 lated eyes, and by the pearly nature of their shells beneath the 

 epidermis and outer layer. They are invariably marine, feeding 

 on the sea-weeds which abound along the shore, and are distrib- 

 uted in all parts of the globe, being most numerous and of larger 

 growth and more beautiful colors in tropical seas. 



The Turbinidse are distinguished from the Trochidae generally 

 by the form of the shell, and by the operculum, which is calca- 

 reous and paucispiral in the former, corneous and multispiral 

 in the latter. The arrangement-of the groups of both families 

 corresponds with that proposed by Dr. Paul Fischer in his 

 excellent monographies of Trochus and Turbo. 



Turbo, Linn. 



Top-shell. Etym. — Turbo^ a whipping top. 



l^istr. — 76 recent sp. World-wide in tropical seas. Fossil, 

 400 sp. L. Silurian — ; universally distributed. T. iniai-mor- 

 atus, Linn. (Ixxix, 10). 



Shell turbinated, solid; whorls convex, smooth or often 

 grooved or tuberculated ; aperture large, rounded, slightl}^ pro- 

 duced in front. Operculum shelly and solid, callous outside, and 

 smooth, or variously grooved and mammillated, internally horny 

 and paucispiral. In T. sarmalicus the exterior of the operculum 

 is botryoidal, like some of the tufaceous deposits of petrifying 

 wells. 



TURBO (restricted). Shell smooth, or tuberculate, covered by 

 a smooth epidermis; inner lip flattened, more or less produced 

 'in front ; no umbilicus. Operculum spiral on its inner face, 

 convex and smooth or granular (not ridged) externall}^ 1*7 sp. 

 Indian and Pacific Oceans, W. Indies. 



The "green snail " of the dealers, the Turbo- mciVmorotus, is 

 very largely used for ornamental purposes. Slices of this shell 

 ground down to a thin surface, are emploj'^ed for covering or 

 inlaying various articles, such as small stamp-cases, fancy boxes, 



