264 HISTORICAL PALEONTOLOGY. 



23) ' Sur les Belemnites. ' Blainville. 



,24) ' Cephalopoden. ' Quenstedt. 



(25) ' Mineral Conchology. ' Sowerby. 



(26) 'Jurassic Cephalopoda' ( Palseontologica Indica). Waa- 

 gen. 



(27) ' Manual of the Mollusca. ' Woodward. 



(28) ' Petref aktenkunde. ' Schlotheim. 



(29) ' Bridgewater Treatise. ' Buckland. 



(30) ' Versteinerungen des Oolithengebirges. ' Rcemer. 



(31) 'Catalogue of British Fossils.' Morris. 



(32) ' Catalogue of Fossils in the Museum of Practical Geol- 



ogy. ' Etheridge. 



(33) ' Beitrage zur Petrefaktenkunde. ' Miinster. 



(34) ' Petrefacta Germanise. ' Goldfuss. 



(35) ' Lethaea Rossica. ' Eichwald. 



(36) 'Fossil Fishes' (Decades of the Geol. Survey). Sir 



Philip Egerton. 



(37) ' Manual of Palaeontology. ' Owen. 



(38) ' British Fossil Mammals and Birds. ' Owen. 



(39) ' Monographs of the Fossil Reptiles of the Oolitic For- 

 mation.' (Palseontographical Society). Owen. 



(40) ' Fossil Mammals of the Mesozoic Formations ' Palae- 



ontographical Society). Owen. 



(41) 'Catalogue of Ornithosauria. ' Seeley. 



(42) " Classification of the Deinosauria " ' Quart. Journ. Geol. 

 Soc., ' vol. xxvi., 1870. Huxley. 



CHAPTER XVII. 

 THE CRETACEOUS PERIOD. 



The next series of rocks in ascending order is the great and 

 important series of the Cretaceous Rocks, so called from the 

 general occurrence in the system of chalk (Lat. creta, chalk). 

 As developed in Britain and Europe generally, the following 

 leading subdivisions may be recognized in the Cretaceous 

 series : 



1. Wealden. 1 T 



2. Lower Greensand or Neocomian, } Lower Cretaceous. 



3. Gault, 



4. Upper Greensand, 



5. Chalk, > Upper Cretaceous. 



6. Maestricht beds, 



I. Wealden. The Wealden formation, though of consider- 



