FOSSIL MOLLUSC A. 



269 



muddy ooze (now white chalk) of the Cretaceous 

 sea-bed, to which its valves could be attached. It 



Fig. zso.—Turiielia 

 Fig. 249. — Dianchora striata (Cretaceous). gramilata (Greensand). 



was thankful to settle down as spat on any surface 



Fig. 7.^x,-'Spo7tdyIus spinosus. 



Fig. 252. — Chama squamosa (Lower 

 Cretaceous). 



Fig. 253.— Gervillea anceps (Greensand). 



which presented itself — whether a dead "fairy-loaf," 

 the bone of a decomposed cuttle-fish (Belemnite), the 



