5 
PECTEN similis. 
TAB, CC V.—Fig. 6. 
Spec. Char. Suborbicular, depressed, striated ; 
striae arched, diverging; ears unequal; sides 
straight. 
This differs from the last in having a straight side be- 
neath. the larger ear, in being longer, and having no dots 
in the striae ; but at first sight it much resembles it 
Upon shelly Limestone, probably belonging to the 
Forest Marble, from Shotover Hill, Oxford. 
PECTEN rigida. 
TAB. CC V.—Fig, 8 . 
Spec. Char. Orbicular, depressed ; strongly 
striated; striae arched, diverging; ears large, 
unequal, decussated. 
A larger shell than the last, which it resembles, but is 
shorter, and has fewer and deeper striae. 
From Castle Combe, in Forest Marble, by favour of 
the Rev. H. Steinhauer. 
