95 



PECTEN asper. 

 TAB. CCCLXX.— i^^v. 1. 



Spec. Char. Nearly orbicular, convex on 

 both sides, bearing about 17 sets of rays 

 roughened by subtubular imbricated scales ; 

 margin internally fimbriato-crenated ; ears 

 distinct, nearly equal. 

 Syn. Pecten asper. JLamarck Hist. Nat. VI. 



180. Lister Conch, t. 470. f. 28. ' 

 The rays are from 5 to 7 in a set, depending upon the 

 age of the shell ; the centre of each set has the largest 

 scales, and is much elevated ; the contour is oblique, 

 much resembling that of the common P. opercularis. 

 The inside is plain -with afurbelowed margin. 



Very abundant in the Green Sand, especially at Horn- 

 ingsham near Frome. Lamark describes P. asper as 

 having 20 to 22 rays ; this is not the case in the English 

 specimens. 



PECTEiN obliquus. 

 TAB. CCCLXX.— i^io.2. 



Spec. Char. Obliquely oval, convex on both 

 sides ; radii very numerous, roughened by 

 semicircular imbricated scales ; ears large, 

 distinct. 

 Every third ray is larger than the two intermediate 

 ones, they are all close together, the larger amount to 

 about 20. The two valves are not equally convex, but 

 otherways they are similar ; the breadth it about two- 

 thirds the length. 



Drawn many years ago from a specimen in green 

 sand belonging to my lamented friend Mr. Cunnington, 



