FOSSIL MARINE SHELLS. 669 
Turbo littpreus. 
rudis. 
teretra. 
Area minuta. 
nucleus. 
Patella pellucida. 
vulgaris. 
Buccinum lapillus. 
Mytilus edulis. 
Pecten opercularis. 
Venus Islandica. 
Venus striata. 
literata. 
Balanus communis. 
Buccinum undatum. 
Anomia ephippium, 
Tellina plana. 
Cardium echinatum, 
Nerita littoralis. 
glaucina. 
Mya truncata. 
Trochus erassus. 
All these still inhabit the Frith of Clyde and its shores, 
but occur only below Dumbarton, or where the water is 
constantly salt. 
