Trochus. MOLLUSCA. TROCHUSID^E. 



T. lineatus (Da Costa, Brit. Conch. 100. t. vi. f. 7-), Don. Brit. Shells, 



t. 71 — T. crassus, Mont. 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 to!;Montagu there is a sort of plume 

 behind the left eye, composed of simple contiguous fibres. 



- 286. T. papittosus. — 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 strife are slightly decussated 

 by the lines of growth ; base with numerous, spiral grooves, finely striated 

 across by the lines of growth ; aperture slightly angular ; pillar-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, spiraDy 

 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 ao-o bv Dr 

 Leach, with the name T. Lt/onsii, 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 |ths ; crimson-red, with white spots ; 

 whorls with four smaller slightly tuberculated spiral ridges, the intervening 

 spaces pitted ; base with nearly smooth spiral striae, 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. Pull. 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 jjths ; grey, with transverse waved black 

 lines ; spiral stria?, 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. 



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