A Manual of Elementary Geology / or, The Ancient Changes of the Earth and its Inhabitants as Illustrated by Geological Monuments

by Sir Charles Lyell

Clausilia bidens. Loess.

Fig. 49.

Bulimus lubricus. Loess, Rhine.

The terrestrial shells are all univalves. The most abundant genera among these, both in a recent and fossil state, are Helix ([fig. 45.]), Cyclostoma ([fig. 46.]), Pupa ([fig. 47.]), Clausilia ([fig. 48.]), Bulimus ([fig. 49.]), and Achatina; which two last are nearly allied and pass into each other.

Fig. 50.

Ampullaria glauca, from the Jumna.