TIIK CRETACEOUS SYSTEM 471 



Cephalopoda. Holcostephauus (Astieria) Astiori, H. (Simbirakites) 

 Decheni, H. (Sirabirskites) versicolor, Hoplites 

 speetouensis, Crioceras Duvali, Belemnites jaculuin. 



Fossils of the Hoplites Dcshayesi zone 



Lamellibranehia. Grammatodon securis, Corbula angulata, Nucula 



subangulata. 

 Cephalopoda. Hoplites Deshayesi, Hoplites furcatus, Ancyloceras 



gigas, Belemnites brunsvicensis, B. Jasekowi. 



Lastly there is the freshwater facies of the English and German 

 Wealden which represents the terrestrial and lacustrine life of the 

 period. 



Fossils of the Wealden Beds 



Plantae. Chara Knowltoni, Equisetites Lyelli. Filices : Onychiopsis 

 Mantelli, Matonidium Gcepperti, Cladophlebis Albertsi, 

 Sphenopteris Fittoni, Tempskya Schimperi, Weichselia 

 Mantelli. Cycadacece : Cycadites Rcemeri, Dionites Dun- 

 kerianus, Nilssonia Schaumburgensis, Otozamites Klip- 

 steini, Zamites Buchianus, Anomozaraites Lyellianus. 

 Coniferae : Piuites Dunkeri, Sphenolepidium Kurrianuni. 



Crustacea. Cypridea valdeusis, Cythere Fittoni, Estheria elliptica. 



Gastropoda. Viviparus fluviorum, V. cariniferus. 



Lamellibranehia. Cyrena media, C. elongata, Unio valdensis, U. com- 

 pressus, U. aduncns. 



Pisces. Lepidotus Fittoni, Hybodus dubius. 



Reptilia. Iguanodon Mantelli, Hypsilophodon Foxi, Ceteosaurus 

 brevis, Hylaeosaurus Oweni, Megalosaurus Bucklandi, 

 Goniopholis crassidens, Chelone Mantelli. 



B. BRITISH REPRESENTATIVES 



In England the Lower Cretaceous rocks occupy a much smaller 

 surface-area than those of the Upper Series, but that is largely due 

 to their overlap by the base of the Upper Series. The subterranean 

 extension of the Lower Series is of importance, because the sands in 

 its higher part are water-bearing, and borings have frequently been 

 made in search of them. As a result of the borings already made, 

 its subterranean extent in the east of England is now fairly well 

 known ; thus though these sands are present at Chatham they are 

 absent at Streatham and also on the north side of the Thames 

 beneath Middlesex, Essex, and the south of Suffolk. TLey were 

 found, however, in borings near Windsor, at Hitchin, at Culford 

 near Bury St. Edmunds, and recently at Lowestoft. Hence they 

 probably underlie the whole of Cambridgeshire and Norfolk, 

 and extend far under the North Sea east of Lincolnshire and 

 Yorkshire. 





