BIVALVIA. 177 
This appears to differ from sgvamosa in having rather more fimbriated lamella, but it 
is doubtfully distinct. M. Deshayes has united two shells previously considered by 
himself as specifically separated. From this I presume the French specimens present 
great variations. Our specimen appears to be intermediate between the two varieties 
rusticula and substriata. 
8. Cnama prisca, 8S. Wood. Pl. XXV, fig. 10. 
Locality. London Clay. Railway-cutting, Finchley. 
The figure referred to represents a small shell received from Mr. Edwards with the 
above locality attached. his is the first specimen that either Mr. Edwards or myself 
have seen from any Eocene deposit in England below the beds of either Barton or 
Bracklesham. It is the upper valve, and has been somewhat rubbed. Its imperfect con- 
dition unfits it for satisfactory specific determination, but I imagine it to be distinct, from 
its strongly marked radiations and its imperfect or obsolete concentric fimbri. 
