13 



B. with a comprefled white fliell, with the compart- 

 ments ftrongly ribbed ia an oblique direftion to each 

 other, and finely ftriated acrofs the ribs : the margin of 

 the bafe irregularly ferrated : aperture oblique, perfeftly 

 clofed by an operculum, and fo obfcured that it is diffi- 

 cult to find, except when alive. Diameter a quarter of 

 an inch, rarely fo much. 



This fingular and curious fpecies, was firfl publicly 

 noticed by Mr. Pennant as an Englifh fhell, from the 

 Portland Cabinet. Doftor Pulte>jey fays, he has feen 

 it common on oyjlcrs, but more frequently on the OJlrea 

 Opercularis, both from Weymouth and from Poole. 



We have found it not uncommon upon various fliells 

 on the South coaft of Devon, particularly in Salcomb 

 bay ; and fometimes in clufters on the roots of algce. 



It is not uncommon on the coaft o^ Sandwich in Kent, 

 from whence we have received it; and Mr. Walker 

 obferves it is found on the roots of Sea-weeds ; the fineft 

 fpecimens on lohjlers. 



10. 



Lepas Diadema. Lin. SyJI. p. 119S. — G/>;eI. Syji. p. 3208. Diadema. 

 C/iem. Conch, viii. t. 99, f. S43. 844. 

 Lijicr. Conch t. 445. f. 2SS. 

 G^ialt. t 106 f. Q. 

 Ph. Tranf. 1758. pt. 2d. t. 34. f. 1. 



Lepas 



