3G4 LITTORINIDiE. 



nacreous deposit of carbonate of lime natural to the 

 shell/' The tongue is remarkably long and slender in 

 proportion to the size of the body — more than three 

 times its length. The operculum^ resting on a ledge, is 

 never sunk within the shell. 



It is the Turbo petrceus of Montagu^ T. C(E7mIescens of 

 Lamarck^ L. Basterotii of Payraudeau, Helix neritoidea 

 and T. Lemani of Delle Chiaje, T. petreus of Fleming, 

 L. melanostoma of Krynicki, and T. petricola of Leach. 



3. L. ru'dis"^, Maton. 



Turbo rvdis, Maton, Nat. Hist, and Antiq. West. Count, i. p. 277. L. 

 rudis, F. & H. iii. p. 32, pi. Ixxxiii. f. 1-7, & Ixxxvi. f. 1. 



Body of various hues, white, yellow, brown, or fleshcolour, 

 usually more or less clouded or streaked across with dark 

 purple : head thick, wrinkled transversely, often tinged with 

 violet on the upper part and neck : tentacles rather slender, 

 with blunt tips, frequently marked with a pale-yellowish or 

 black stripe in front down the middle, and with another of a 

 similar colour on the under side : eyes globular and prominent, 

 on short and thick stalks, which are amalgamated with the 

 tentacles at their outer bases ; pupils black, within gelatinous 

 and transparent irides : foot double-edged in front ; sole hght- 

 yellow or whitish, bordered by a clear hem at the sides and 

 behind, and divided down the middle by a sHght fold. 



Shell forming a short cone, sohd, opaque, and lustreless : 

 sculpture, several flattened spiral ribs, crossed obliquely by 

 slight, irregular and laminar marks of growth ; the surface is 

 covered with close-set minute spiral wavy striae or wrinkles, 

 which are always discernible in every form of this extremely 

 variable species : colour most diversified, consisting chiefly of 

 yellow, brown, red, orange, and purple, sometimes jet-black 

 or pure white, and usually variegated by zones or spiral bands 

 of diff'erent hues and widths : epidermis not observable, and (if 

 formed) probably a mere film and caducous : spire moderately 

 pointed : luhorls 6-9, convex, somewhat flattened or compressed 

 just below the suture ; the last whorl occupies in the female 



* Eough. 



