356 LITTORINIDjE. 



respect to species of Helix and Pupa among the Pulmo- 

 nobranchiata*. The Littorina are extremely prolific, and 

 found in all parts of the world. According to Nyst, out 

 of the 59 species known in 1843 (when he published his 

 excellent catalogue of the fossil shells and polypes of 

 Belgium) 37 were recent, 8 from tertiary, 10 from cre- 

 taceous, and 1 from carboniferous strata. The Messrs. 

 Adams have lately enumerated 56 recent species ; but 

 some of these are only recognized by other conchologists 

 as varieties. 



Menke changed the spelling of the generic name to 

 Litorina a pedantic and unnecessary innovation. Lit- 

 tus and Litus were used indifferently by the best Latin 

 writers. Cicero seems to have preferred the former 

 mode of spelling ; Ovid has both. 



\te- 1. LITTORINA OBTU'SATA LinneJ (s&r) - K- 3 



Turbo obtusatus, Linn. S. N. p. 1232. L. litoralis, F. & H. iii. p. 45, 

 pi. Irriv. f. 3-7, and p. 49, pi. Ixxxvi. f. 2, 3. 



BODY yellowish- white, lemon or orange-yellow, often tinged 

 with purple or violet, rarely sootcolour, and marked across 

 by lines of a paler hue : mantle sometimes edged with orange 

 or black : head narrow, occasionally reddish or neshcolour on 

 the upper part or neck : tentacles tapering, with blunt whitish 

 tips ; their sides are in some specimens bordered by fine lead- 

 coloured lines : eyes small, with pearl-white irides and black 

 pupils : foot broader in front, and bluntly pointed behind, 

 somewhat contracted at about one-third of the way down ; 

 sole pale yellow, yellowish- white, or whitish, divided length- 

 wisejn the middle by a slight line, which resembles a crack 

 in the glaze of an earthenware dish : opercular lobe now and 

 then sinuated or finely cloven. 



SHELL nut-shaped, thick, opaque and lustreless : sculpture, 

 numerous minute fine, but irregular, spiral wavy striae, which 

 are mostly observable on young and immature specimens ; the 

 crossing of these striae by the lines of growth causes a slight 



* See vol. i. pp. 222 and 248. t Blunted. 



