288 



T. with a thin, conic fliell, of a livid-white colour, witFr 

 five or fix volutions nearly flat, finely ftriated longitudinally 

 divided by a very finall deprelFed line, and a prominent 

 ridge at the bafe of each : apex produced, but not very 

 pointed: aperture much comprclfed. angulated : bafe flat, 

 ftriated from the centre . umbilicated : round the bafe a 

 ftrong carinated edge. Diameter rather more than a quar- 

 ter of an inch ; height not quite fo much. 



There can be little doubt but this is the fame as that 

 found by Morton in NoTihaynptoiiJhire, and afterwards 

 by Mr. Hudson in the mountains o^ Cumberland, com- 

 municated to Mr. Pennant. Da Costa does not ap- 

 pear to have been acquainted with this fliell, but has taken 

 his defcription from the authors above quoted. He alfo 

 gives another fpecies, which he calls Trochus terre/lris 

 Lijleri, and quotes Lister's Anglica, Morton's North- 

 mnpton, and the Philofop/ncal Iranfadions. This we ars 

 inclined to think is our Helix trochiformis. 



The Trochus terrcjlris is the only true land fiiell of 

 that genus found in England, and may be confidered 

 as very rare. It may not however be improper to remark 

 in this place, that many of the long Turbines may readily 

 be miflaken for Trochi in their infant flate, when only 

 three or four volutions are formed ; the bafe of which is 

 generally flat, and the aperture tranfverfely comprefled. 



Such we have frequently received from our friends for 

 new fpecies of Trochi; in particular the Turbo Mujcoi'-um. 



Trochus 



