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

by Sir Charles Lyell

Fig. 231. Crown of tooth in adult, worn down. (Mantell.)

Occasionally bands of limestone, called Sussex Marble, occur in the Weald Clay, almost entirely composed of a species of Paludina, closely resembling the common P. vivipara of English rivers.

Fig. 232.

Cypris spinigera, Fitton.

Fig. 233.

Cypris Valdensis, Fitton. (C. faba, Min. Con. 485.)