Ch. XVII.] FOSSILS OF UPPEK CEETACEOUS ROCKS. 



245 



and some of the genera, like Ananchytes (see fig. 253), are exclusively 

 cretaceous. Among the Crinoidea, the Marsupite (fig. 260) is a charac- 



Fig. 254 



Fig. 255. 



Hicraster cor-anguinum. 

 White chalk. 



Galerites albogalemis, Lam. 

 "White chalk. 



teristic genus. Among the mollusca, the cephalopoda, or chambered 

 univalves, of the genera Ammonite, Scaphite, Belemnite (fig. 256), Bacu- 

 lite (257-259), and Turrilite (262, 263), with other allied forms, present 

 a great contrast to the testacea of the same class in the tertiary and recent 

 periods. 



Fig. 256. 



a 6 



a. Belemnites mucronatus. 



&. Same, showing internal structure. Maestricht, Faxoe, and white chalk. 



Fig. 257. 



Baculites anceps. Upper greensand, or chloritic marl, craie chloritee. France. 

 A. D'Orb. Terr. Cret. 



Fig. 253. 



Portion of Baculites Faujasii. 

 Maestricht and Faxoe beds and white chalk. 



Fig. 259. 



Portion of Baculites anceps. 

 Maestricht and Faxoe beds and white chalk. 



Fig. 260. 



Fig. 261. 



Marsupites Miller i. 

 White chalk. 



ScapJiites cequali*. Chloritio 



marl of Upper G-reensand, 



Dorsetshire. 



