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

by Sir Charles Lyell

Gryphæa incurva, Sow. (G. arcuata, Lam.)

Fig. 305.

Nautilus truncatus. Lias.

The name of Gryphite limestone has sometimes been applied to the lias, in consequence of the great number of shells which it contains of a species of oyster, or Gryphæa ([fig. 304.], see also [fig. 30.] [p. 29.]). Many cephalopoda, also, such as Ammonite, Belemnite, and Nautilus ([fig. 305.]), prove the marine origin of the formation.

Fig. 306.