Ce. xvii.] fossils of upper cretaceous 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. 



Micrnfder cor-avguinum. 

 White chalk. 



Galerites alhogalerxis, Lam, 

 White" chalk. 



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

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

 lite (257-259), and Turrihte (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 5 



^^^^^^ 



a, Belemnites mucronatus. 



b. Same, sliowing internal structure. Maestricht, Faxoo, and white chalk. 



Fig. 2o-. 



^ 



^t^\^^3;a-vVU-iL^^ \^-Amg?aja 



BacuUtes anceps. Upper greensand, or chloritic marl, crai6 chloritee. France. 

 A. DOrb. Terr. Cret. 



Fig. 258. 



Portion of Baculites Faujasii. 

 Maestricht and Faxoe beds and wliite chalk. 



Fig. 259. 



Portion of BacuUtes anceps. 

 Maestriclit and Faxoe beds and white challc 



Fig. 260. 



Fig. 2G1. 



Marsupites MiUeri. 

 White chalk. 



ScapJiifes a>quaUs. Chloritio 



marl of Upper Greensand, 



Dorsetshire. 



