4'69 



volution, and is loft in the future, or divKion, towards 

 the apex ; between the ridges, the fliell is finely ftriated 

 acrofs the fpires ; from the lower ridge, at the bafe, com- 

 mences a deprelTion, or femi-circular channel, which 

 finks into a deep and large umbilicus: aperture oval; 

 outer lip projecting confiderably ; inner lip reflefted, 

 and fpreading into a fharp angle, elevated on the body- 

 whirl. The mouth, as well as the whole fliell, is thick 

 and ftrong for its fize. Diameter at the bafe one tenth 

 of an inch ; height rather more than half as much. 



This fingular, and curious fpecies, has much the ha- 

 bit of a Nerita, but the form of the aperture gives it a 

 a place amongft the Helices. 



We have found it fparingly amongfl fine fand from 

 Salcomb bay, Bigberry bay, and Milton fands, on the 

 fouth coafl: of Z)(?w;z ; and have received it from Dover 

 in Kent, of a very inferior fize, found on that coaft by 

 Mr. Lyons. 



45. 

 H. with a depreffed, fub-pellucid fliell, of a light- Depressa. 

 brown colour: volutions three or four; the fuperior Tab. 13. f. 5, 

 ones fcarce elevated above the body, but well defined 

 by the feparating line, and (lightly wrinkled : apex very 

 confpicuous, but very little raifed, or produced ; lower 

 volution perfe6lly round or cylindric, fo as to form a 

 large umbilicus, in which the others are diftinflly feen : 



aperture 



