86 
PRODUCTA depressa. 
TAB. CCCCLI X.—fig. 3. 
Spec. Char. Nearly semicircular, depressed, 
corrugated, longitudinally striated ; upper 
portion convex near the beak, concave near 
the margin ; front abruptly descending. 
Syn. Producta depressa, Sowerbys Genera . 
The numerous strise and concave space around the 
margin of the upper part, are the distinguishing charac- 
ters of this species; the front although it descends 
suddenly, is not very deep ; the hinge line is long, and 
the sides so expanded near it as almost to form ears ; it 
has no spines. 
The four views before us of this Producta, will serve 
to illustrate the Genus further than any previously given 
in this work ; those of the inside shew the muscular im- 
pressions, with the processes near the hinge in the upper 
valve, and the crenulated hinge line in the other, which 
has also two elevations bounding the cicatrices of the 
muscles; they are all taken from two masses of Dudley 
Limestone, but are grouped together so as to occupy 
less space, and the essential parts made rather conspicu- 
ous. 
I know of no other species in the Dudley Limestone, 
neither is this found in any other place. 
