TROCHUS. 525 



minutely fringed margins ; a groove runs down the anterior 

 half of its length. The rows of denticles on the lingual 

 riband of this species are set very oblicmely on each side 

 of the central one, which has a broad base, a narrow but 

 not contracted neck and a broad but shallow hook. The 

 general character of the dentition approaches, but is very 

 distinct from, that of cinerarius. 



This fine shell is found all round our coasts, though 

 not everywhere in equal abundance. It is most vividly 

 coloured in southern localities. A white variety was 

 noticed by Mr. Jeffreys in the Hebrides and Zetland. It 

 lives in from three to twenty-five fathoms water, and is 

 most abundant in from ten to fifteen fathoms. It is not 

 known north of the British Isles, but ranges southwards to 

 the Mediterranean. It has not been found fossil in our 

 tertiaries. When artificially decorticated, so as to expose 

 the nacre, it is sometimes made into ornaments, such as 

 brooches and. bracelets, with fine effect. 



T. lineatus, Da Costa. 



Orbicular-conoid, strong, smooth, imperforated ; painted with 

 flexuous linear markings. 



Plate LXV, fig. 4, 5, as T. crassus. 



Turbo lineatus, Da Costa, Brit. Conch. (1778) p. 100, pi. 6,f. 7.— Donov. Brit. 



Shells, vol. ii. pi. 71 • 

 Trochus crassus, Pulteney, Hutchins, Hist. Dorset (1799), p. 44. — Mont. 



Test. Brit. p. 281. — Maton and Rack. Trans. Linn. Soc. 



vol. viii. p. 154. — Rack. Dorset Catalog, p. 48, pi. 17, f. 3, 7. 



— Tukt. Conch. Diction, p. 188. — Fleming, Brit. Anim. p. 



322.— Brit. Marine Conch, p. 162.— Brown, Illust. Conch. 



G. B. p. 19, pi. 11, f. 6, 7.— Dillw. Recent Shells, vol. ii. 



p. 796.— Wood, Index Test. pi. 29, f. 87. 

 Monodonta lugubris, Lam. Anim. s. Vert. (ed. Desh.) vol. ix. p. 180. — Dei.es. 



Rec. Coquil. Lam. pi. 36, f. 7. 

 Trochus punclulatus, Bi.ainv. Faune Franchise, Moll. p. 270. pi. 11, f. 2. 

 Monodonta crassa, Macgiluv. Moll. Aberdeen, p. 325. 



