297 



length of the fhell, with from nine to twelve regular, and 

 diftant, high, membranaceous ribs, running a little oblique: 

 aperture orbicular, margin thickened by a rib that fur- 

 rounds it : colour white, fometimes with a few brown 

 markings. Length an inch and an half; breadth at the 

 bafe half an inch. Exotic fpecimens are frequently larger, 

 and have the ribs and markings flronsjer. 



This elegant fpecies, which much refembles that once 

 coftly and much coveted fliell, the Wentlc-trap, is found 

 on feveral parts of our coaft, but no where plentiful. We 

 have taken it at Falmouth in Cornwall, and on the fliores 

 oi South Devon; but feldom perfeft, except fmall ones. 



Young recent fpecimens are beautifully white, and 

 poliflied between the ribs. 



Da Costa fpeaks of it as plentiful on the eafterncoalls 

 of Wales, and in Scotland. Is alfo found in DorfelfJiire 

 and Kent, 



4. 

 Turbo clathratus fex anfraftibus apertura ovali marglnata. CLATHRATUi.r=; 



Walk. Min Shells, f. 45. 

 Turbo Clathratulus. Turt. Lin. iv. p. 500. 



Adams Mkrofc. t. 14. f. 19. 



This fpecies originally defcribed by Mr. Walker, dif- 

 fers in nothing from the preceding, except in fize, and in 

 the number of volutions, and ribs. We were firft fa- 



Q q soured 



