153 



to remark in this place that recent occurrence has induced 

 us to believe that what we had formerly confidered as the 

 older ftiells of Patella pellucida are a6tually difti t^l ; and 

 therefore requeft that they may be feparated, and that the 

 fynonyms of candea affixed to pellucida in Tejiacea Britan- 

 nica may be transferred to this. It muil be obferved that 

 the principal dirtin<^iiun of the pellucida is the regular ovate 

 and convex appearance, with fcarcely any obvious beak ; 

 but what little it has is always clofe to the margin : befides 

 it is always pellucid, and feldoni has more than four or five 

 blue lines. The carulea on the contrary is extremely va- 

 rious in its fhape at all ages, fome being much deprefTed, and 

 others greatly elevated, and the beak is never fo low as to 

 be deftitute of margin. It is alfo ufually rayed from the 

 vertex on all fides, fometimes with a few blue lines, and the 

 reft brown : the beak is generally decorticated even in the 

 fmallfcfl fpecimens, and often Hands abrupt as if a fmall 

 fhell was placed upon a larger. In this abrupt apex, one, and 

 fometimes tv;o black fpots are obferveable, efpecially when 

 worn ; and when this part only remains of the fliell, having 

 by accident been feparated ; or being much thicker has been 

 left after the reft has been worn away, recent obfervation 

 has inclii .ed us to believe is what we originally confidered 

 to be a dcftin6l fpecies, and defcribed in the former part of 

 this work under I he title of bimaculata. We are iupported 

 in this opinion by the obfervation of Mr. Laskey, who has 

 had frequent opportunity of noticing it on the fliores of 

 Scotland. This being admitted, the Patella bimaculata rnuft; 

 be t-rafed from the catalogue of Britijljjljells. 



V Intorta. 



