C 26 ] 
O S T R E A. 
Bivalves; with unequal valves ; viz, one Jlatj the 
other concave, 
^ Without ears. Oyjler, 
F I G. XXXV. 
A. B. Crooked near the hinge, then dilated i 
lower valve with feveral ridges parallel to the 
margin. 
Found in clay banks on the fides of hills: 
commonly with their valves apart. 
FIG. XXXVI. 
A. B. Round: lower valve very concave; 
formed of one or two imbricated plates. 
Found with Fig. 35. 
Mr. Jos. Glanville, in an account of the 
Baths in Somerfetfliire, fays, it is affirmed here, 
(in the city of Bath) that the town for the 
moil part is built upon a quagmire, though the 
places all about it are very firm ground. Some 
workmen, that have been employed in digging, 
have 
