FOSSIL CEPHALOPODS. 319 



The Gault near Folkestone is a magnificent store- 

 house of fossil Cephalopoda. Both on the beach and 

 in the brick pits on the common any quantity of 

 fossils can be obtained. The Ammonite family seems 



Fig. 325. Fragments of Hamites attenuatus. 



to run into strange and fantastic external forms in 

 the Cretaceous strata, commencing with the Lower 

 Greensand, and passing upwards through the Gault, 



Fig. 326. Tutrilites Bergerii. 



Fig. 327. Turrilites iindulatus. 



Upper Greensand, and Lower Chalk. The regularly 

 coiled Ammonites now become irregular. Sometimes 

 they are only partly coiled, as in Crioceras ; at others 

 hooked at one end, as in Hamites, or coiled up at 



