Trochus. 
MOLLUSCA. TROCHUSIDjE. 
923 
T. lineatus (Da Costa, Brit. Conch. 100. t. vi. f. 7.), Dora. Brit. Shells, 
t. 71 T. crassus, Mmt. Test. Brit. 281 — English coast, on rocks 
about mid tide. 
Length and breadth about an inch ; purplish-brown, with numerous white 
zigzag lines ; shell strong, whorls coarse and wrinkled by the lines of 
growth ; base convex ; aperture rounded ; pillar lip concave in the middle, 
in front of which is the tooth. According tofMontagu there is a sort of plume 
behind the left eye, composed of simple contiguous fibres. 
286. T. papillosus. — Whorls eight, flat, with numerous spi- 
ral tuberculated ridges and striae. 
{Da Costa, Brit. Conch, p. 38. No. 20. t. iii. f. 3.) Don. Brit. Shells, 
t. cxxvii. — T. tenuis, Mont. Test. Brit. 275. t. x. f. 3.— South coasts 
of England and Ireland. 
Length l|th inch, breadth rather less ; pale reddish-brown, with red spots ; 
whorls scarcely distinguished by the separating line ; the tubercles on the 
ridges are transverse, smooth, the intervening strije are slightly decussated 
by the lines of growth ; base with numerous, spiral grooves, finely striated 
across by the lines of growth ; aperture slightly angular ; piUar-lip concave. 
287. T. ziziphinus. — Whorls eight, flat, separated by a 
smooth circular ridge, obsoletely striated spirally. 
T. albidus. List. An. Ang. 166. t. iii. f. 14. Conch, t. Dcxvi. f. 1.— 
T. ziz. Linn. Syst. 1231. Mont. Test. Brit. 274 — Not uncommon, 
near low water mark. 
Length and breadth about an inch ; livid, the separating ridge with darker 
and lighter coloured spaces; spire conical, pointed; base smooth, spirally 
striated with diverging curved lines of growth ; aperture quadrangular ; 
the pillar-lip slightly concave, with an obsolete tooth at the anteal extre- 
mity — A white variety of this shell was sent me several years ago by Dr 
Leach, with the name T. Lyonsii, from Tenby. 
288. T. exasperatus. — Whorls seven, flat, separated by a 
tuberculated circular ridge. 
T. pyramidalis parvus. List. Conch, t. Dcxvi. f. 2 — T. exasp. Penn» 
Brit. Zool. iv. 126 — T, conulus, Don. Brit. Shells, t. viii. f. 2. — T. 
exiguus, Mont. Test. Brit. 277 — Southern coasts, rare. 
Length |ths of an inch, breadth fths ; crimson-red, with white spots ; 
whorls with four smaller slightly tuberculated spiral ridges, the intervening 
spaces pitted ; base with nearly smooth spiral stri^, slightly convex where 
the body-whorl enters the aperture. 
289. T. striatus.- — Whorls seven, flat, with an indistinct 
separating ridge, smooth on its upper surface. 
Linn. Syst. i. 1230. Pult. Dorset, p. 44. Mont. Test. Brit. 278.— T. 
conicus, Don. Brit. Shells, t. civ. f. 1. — T, erythroleucos, Turt. Conch. 
Diet. 191 On the southern coasts. 
Length |ths of an inch, breadth fths ; grey, with transverse waved black 
lines ; spiral strise, on the base and surface of the whorls, numerous, crossed 
by sharp oblique lines of growth, which extend across the outer edge of the 
separating ridge; base flat, the body -whorl, where entering the aperture, 
slightly concave ; aperture angulated. 
X 2 
