24.6 FOSSILS OF UPPER CRETACEOUS ROCKS. [Ch. XVII. 



Fig. 262. Fig. 263. 



Turrilites costatus. 

 Chalk. 



a. Fragment of Turrilitea costatus. 

 Chalk mail 



6. Same, showing the indented border 

 of the partition of the chambers. 



Among the brachiopoda in the white chalk, the Terebratulce are very 

 abundant. These shells are known to live at the bottom of the sea, where 



Fig. 2G4. 



Fig. 265. 



Terebratula Befrancii. 

 Upper white chalk. 



Terebratula 



octoplicata. 



(Var. of T. plicatilis.) 



Upper white chalk. 



Fig. 26T. 



Terebratula pumilus. Terebratula 

 (Magas pumilus, Sow.) cameo. 



Upper white chalk. Upper white chalk. 



the water is tranquil and of some depth (see figs. 264, 265, 266, 267, 

 268). "With these are associated some forms of oyster (see figs. 2*75, 

 276, 277), and other bivalves (figs. 269, 270, 271, 272, 273). 



Fig. 268. 



Terebratula biplieata, 

 Bow. Upper cretaceous. 



Fig. 269. 



Fig. 270. 



Crania Parisiensis, 

 inferior or attached 



valve. 

 Upper white chalk. 



Pecten JSeaveri, reduced to 



one-third diameter. 

 Lower white chalk and chalk 

 marl. Maidstone. 



Among the bivalve mollusca, no form marks the cretaceous era in 

 Europe, America, and India in a more striking manner than the 

 extinct genus Inoceramus (Catillus of Lam.; see fig. 274), the shells 



