3t)0 



a,Hd when dried and contrafled within, the upper volu- 

 tions only, are of a dufky-brown colour. Old fliells are 

 fometimes worn and decorticated, becoming of a cine- 

 rebus colour in ftreaks and blotches ; but never regularly 

 ftriated, though pod'elTed of faint, longitudinal wrinkles, 

 only obfervable by the affiftance of a lens. 



This fpecies has been confounded with T. bidens and 

 perverfus. Doflor Pulteney, in his Catalogue o^ Dor- 

 Ji/Jhire iheUs, makes it the lafl mentioned; fays it it is 

 much more common than the bidens ; and remarks, that 

 it is much larger than that fliell, and not rarely furniflied 

 with three teeth. Podibly the Doftor had never obferved 

 all the lamince on the outer lip, but only the one on that 

 part niofl: confpicuous. It appears to be very local ; for 

 we have never found it but in Lackham wood, in the 

 north of Wiltjltire, and at Boxo Wood, the feat of the 

 Marquis of Lansdovvn, in the fame county. It is, how- 

 ever, found fparingly in Kent, in the neighbourhood of 

 Sandioich. 



This fpecies is like T. perverfus on the back of the 

 lower whirl, behind the lip, being quite even and round- 

 ed; but its fuperior fize, (hape, and laminated mouth, 

 forbids its being confounded. From T. bidens it differs 

 effcntially, in being fuperior in fize; in tranfparency, 

 gloflinefs, and want of ftriac, as well as in the connexion 

 of the pillar lip to the body ; and the back of the lip 

 being even. 



Animal 



