WORMS. TESTACEA 57. Trochus. m 

 57. TROCHU8. Top Shell. 

 41(5. Tr. ziziphinus. Conic, imperforate at the base 

 spirally striate, the edge of each whorl with a raised 

 smooth margin. 



Br. Zoo!, t. 83./. 103. 104. Donov. t. 52. Da Cofta t. 3./. 3. 4. 



Shell an inch long, nearly as much broad, pointed, with 7 or 8 

 whorls,- livid or pale red varied with darker lines and waves, 

 within iridefcent : aperture angular : bafe flattish, with circular 

 striae, without fpots. 



417. Tr. tenuis. Conic, imperforate at the base, spirally 

 granulate, not margined at the edge of the whorls. 



Montague Brit. Shells, t.. to.f. .3. Donovan t. 1 27. 



Shell an inch and a quarter long, rather less broad, brown or 

 reddish with deeper marks : whorls with feveral rows of minute 

 granulations, but without the raifed ridge at the edge : base with 

 feveral circles of fmall reddish fpots. 



418. Tr. exiguus. Conic, imperforate at the base, spi- 

 rally crenate, the edge of each whorl with a raised 

 tubercled margin. 



. Donovan t. 8.f. 2. Da Dosta t. 2./. 4, lister t. 6\6.f. 2. 



Shell 3 eighths of an inch long, grey-brown or purplish, with the 



' tip crimfon, fometimes fpotted with white; within white, not 

 perlaceous : whorls 6, with 4 or 5 fine crenulate ridges, and edged 

 with a tubercled wreath refembling a twissed cord : bafe with si- 

 circular ridges, 



419. Tr. stnatus. Conic, imperforate at the base, spi- 

 rally ridged and finely striate longitudinally, not 

 margined or tubercled at the edge of the whorls. 



Lister t. 621./, 8. Donovan tab. 155./. 1. 



Size of the last, from which it differs in having 6 whorls hardly 

 definable by the line of feparation, with 8 or 9 fpiral ridges on 



• each, crossed by fine longitudinal striae; in wanting the crimion 

 tip,, and large fpiral rib at the end of each whorl, in being marked 

 by longitudinal reddish lines, and perlaceous within. 



420. Tr. tumidus. Subconic, tumid, slightly perforated 

 at the base, with 5 projecting whorls very finely and 

 spirally striate, the larger-one with a subcarinate 

 edge at the bottom. 



Montague Brit. Shells p. 280. tab. 10./. 4. . 



Shell a quarter of an inch long, strong, .pointed but not taper, 

 grey or yellowish-brown, or dark purplish-brown with obfcure 

 undulations, within perlaceous: bafe rounded, with, a fmalLpex-^ 



• foration which is almost clofed by age. 



421. Tr. crassus. Subconic, rarely perforated at the 

 base, with 5 t rounded smooth, whorls,, grey-brown 

 with numerous, zigzag purplish-brown lines : outer- 

 lip with a tooth-like protuberance at bottom. 



Donov. t.yi. Da Costa t. 6.f. 7. Tr. lineatus. 



Shell strong, coarse, top-shaped, perlaceous when the outer-coat 

 is off: wkorls rounded, separated by a depressed line, marked with 

 close-set* zigzag purplish-brown or black lines : pillar-lip smooth 

 white, not pearly ; the white part extending almost acrofs the 

 base, and flattened as if worn. 



422. Tr. Magus. Subconic, perforated at the base, with 

 5 or 6 tumid whorls, finely striate, the ridges of each 

 rising into obtuse tubercles. 



Br. Z00L t. 80./. 107. Ddnou, t. S.f.t. Da Costa t. $.f. 1. 



