67 
PECTEN lamellosus. 
TAB. CCXXXIX. 
Spec. Char. Orbicular, convex ; with concentric 
erect lamellae upon the surface., and diverg- 
ing' striae near the beaks ; ears large, distinct. 
Both valves are convex, but the lower one is most so ; 
the front is semicircular placed a little obliquely ; the 
straight sides, to which the ears are attached, connive 
to form a right angled beak - when the erect edges of the 
lamellae are broken off, which is commonly the case, 
the shell appears to be constructed of large imbricated 
plaits like an Oyster ; small, irregular, impressed striae, 
which are interrupted and gradually lost towards the 
front, diverge from the beaks. 
I am indebted to Miss Benett for this Pecten ; it 
occurs in the fifth bed of the Limestone of Chicksgrove 
quarry, described in Vol. II. p. 58 ; it is also found at 
Thame, in Oxfordshire, among Sand, of which a very 
large portion is dark green Talc, or Chlorite : this Sand 
belongs to the same stratum as the Limestone of 
Chicksgrove. 
