137 



The contour of this fliell is not unlike T. interuplus, 

 and is fometimes fimilarly marked with faint interupted 

 brown firipes ; the mouth however is different, the outer lip 

 is not fo much expanded, which to2:ether with tlie fpiraly?/7re 

 in perfect fpecimens, are lufficient marks of diftinction. In a 

 worn ftate it might readily be confounded with fome varie- 

 ties of that fliell, and even with coluurlefs fpecimens of 

 T. ruber: indeed there are fo many fmooth Ihells of this fize, 

 moft of which have been polidied by the fand, in conjun6lion 

 with the agitation of the water, that it requires great nicety, 

 and accurate comparative inveftigation to difcriminate; and 

 with every poflible attention, fome diftinft fpecies in the 

 more minute divifion, will probably be omitted for want of 

 fuflScient character. 



Coafl of South Devon, not common. 



Turbo Calcar. Gmel. Syst. p. 3592. Calcar. 



Chem. Conch, v. t. i80. f. 1786-8r. Tab. 29. f. 3. 



Gualt. t. 65. f. N. P. 

 Lister Conch, t. 608. f. 46. a. 



Shell fomewhat compreffed with four volutions, the fupe- 



rior ones deprelTed, forming the fummit flat ; round the 



larger, and part of the fecond whirls, are large, fmooth, 



lanceolate fpines, radiating in ftraight lines from the fhell, 



about thirteen in number : aperture orbicular: bafe convex, 



uniDiiicated: colour pale pink. Diameter a quarter of an 



inch or rather more» 



S A 



