(57 
CHAM. A squamosa. 
TAB. CCCXLVII1. 
Spec. Char. Attached by the right valve ; 
nearly orbicular, subglobose, imbricated ; 
lamella? undivided, somewhat erect, ante- 
riorly produced, and adpressed ; posterior 
part of the right valve obsoletely costated ; 
left valve rather convex ; smooth within. 
Syn. Chama squamosa. Br cinder, 80 and 87, 
Distinguishable from Chama lamellosa of Lamarck, 
who has referred to Brander for his shell, by its undi- 
vided and not even lobed lamella?. 
In the section to which this species belongs the right 
valve is the largest and the one attached to foreign sub- 
stances : by considering this the two sections of the 
genus made by Lamarck will be as readily recognised, 
as by observing whether the beaks turn to the right or 
the left hand, and the definition become more intelligible. 
Extremely common at Barton, where perfect pairs are 
often found : it seldom exceeds in size the specimens 
figured ; it is consequently a smaller shell than C. lamel- 
losa : I have small individuals from some part of France ; 
I think the neighbourhood of Paris ; it is however rare 
in that country* 
