59 



obfolete ribs, befides which the fhell undulates into feVen 

 large elevations, whicli do not feparate the finaller libs, bat 

 are equally covered by them, and befides thefe, it has like" 

 all other varieties the invariable and unerring character, the 

 minute decuflate Jlria:, which are not to be found on either 

 the P. glaber or Icevis^ 



Having acknowledged ourlelves to have been puzzled in 

 the difcrimination of thefe {hells, we do not hefitate to defire 

 thofe fhells defcribed in Tejltxcea Britannica for P. hevis may 

 be confidered as varieties of this fpecies^ 



Pecten glaber, Br. Zool. No, 85].. Glaber. 



p. 150. 

 It will be obferved by every conchologifl that this fpecies Tab. 28. f. 6, 

 originated with Mr. Pennant, and that all fucceeding 

 writers who made mention of it, have been equally in the 

 dark refpe6ling its identity, and therefore could do no more 

 than copy the defcription from the Britiffj Zoology. Wlie- 

 ther the ihell in quefti(;n may be a variety oWflrea glabra of 

 LiNN^us is not to be eafily determined, but we confefs tliere 

 is fome probability, from the fmgular circumftance of the 

 internal double rays, if the fliell hereafter defcribed is the 

 Pewiantian glaber, and of which we have very little doubt, 

 when we confult the variety feveral fpecies of this genus 

 are fubje^l to, as before remarked of the preceding. The 

 fpecimen from which the following defcription and figure is 

 taken, was favoured us by Mr. Laskey, who found it on the 

 Scotijh coafl, near Dunbar, 



H 2 The 



