LITTORINA. 39 



south coasts of Great Britain ; Newbiggin and Salcombe 

 (Alder). 



The animal is of a general yellowish- white hue ; the 

 whole of the upper part of the head is covered with 

 purplish lineations ; the extremity of the muzzle is yel- 

 lowish-white. The tentacles are subulate, yellowish-white, 

 lineated on each side with a fine black stripe ; their bases 

 are much swollen, and bear the eyes on the outer bulgings. 

 A few purplish lines mark the sides under the tentacles. 

 The foot is oblong, rounded at each end, margined in 

 front, and conspicuously grooved in the centre. 



This species is viviparous, and assembles in vast numbers 

 gregariously on rocks at the edge of high water-mark, and 

 often considerably above that limit. Its abundance in 

 many localities where rudis is absent or rare, would seem 

 to bear out its distinctness. It is found all round our 

 coasts, and has a foreign distribution similar to that of its 

 near allies. 



L. TENEBRosA, Montagu. 



Usually more or less thin, very rarely solid ; of an ovate-conic, 

 or oblong-conic shape, the spire being always more or less deve- 

 loped. Whorls six, much rounded, not abruptly enlarging. 

 Mouth rounded oval, its base usually rounded, and not pro- 

 duced : pillar not broadly confluent at its junction with the 

 outer lip. 



Plate LXXXIV. figs. 11, 12; Plate LXXXV. fig. 1 to 5. 



Turbo tenehrosus, Mont. Test, Brit. vol. ii. p. 303 ; Siappl. pi. 20, f. 4. — Maton 

 and Rack. Trans. Linn. Soc. vol. viii. p. 160. — Rack. Dorset 

 Catal. p. 49. — TuRT. Conch. Diction, p. 197, f. 36, 37.— 

 Flem. Brit. Anim. p. 298. — Dillw. Recent Shells, vol. ii. 

 p. 817.— Wood, Index Testae, pi. 30, f. 6. 



„ Uttorcus, Maton and Rack. Trans. Linn. Soc. vol. viii. pi. 4, f. 8, 9 ? 



„ vestitim. Say, Journ, Acad. Philadelph. vol. ii, p. 241. 



