250 



Sow. Th. Pecten.f. 47. P. VITIUEUS. VAR Chemnitz. 

 f. 637. b. Equivalve, suboval, thin, With radiating 

 striae armed with elevated minutely prickly dots ; ears 

 unequal, the anterior small ; the posterior large and in 

 one valve strongly emarginated ; pale yellow clouded 

 with red. 0,8.. .0,9. Oban. 



P.NIVKPS MacgillivrayinEdm.Phil. J. Sow. Th. 

 Monog. Pect.f. 223, 4. Oval white, rather thin, the 

 left valve very slightly the larger ; ears unequal, the 

 posterior rather large; ribs fourty, smooth, quadrate 

 armed with distant erect acute spines; interstices flat. 

 H...l,7. Bears a strong resemblance to Varius. 

 Scotland. 



P. ISABELLA Macgil. Aber. p. 225. Rounded- 

 ovate, subequivalve, little convex, with twenty four 

 slender compressed rounded ribs having very numerous 

 elevated thin edged lamellae rising towards the margin 

 into triangular compressed pointed spines, the grooves 

 with transverse scalar lamellae not extending over the 

 ridges; ears very unequal, with radiating sulci trans- 

 verse lamellae and spines : margin of the upper valve 

 under the auricular sinus with four free curved conical 

 spinelets, of which a series is continued to the smooth 

 and glossy umbo ; white, lower valve tinged with pink. 

 Aberdeen. 0,23.... 0,27. 



