THE CRETACEOUS SYSTKM 497 



Cidaris clavigera, C. perornata, Phymosoma ( = Cypho- 

 soma) radiatuiu, Holaster planus, Micraster Leskei 

 ( = breviporus), M. precursor, M. cortestudinarium, 

 M. coranguimun, Epiaster gibbus. 



Lamellibranchia. Inoceramus involutus, I. Lamarcki, and var. Brongni- 

 arti, Lima Hoperi, L. divaricata, Plicatula Barroisi. 



Gastropoda. Solariella gemmata, Trochus Schltlteri, Cerithiuni 



Saundersi. 



Cephaloj>oda. Heteroceras reussianum, Scaphites Geinitzi, Baculites 

 bohemicus. 



Fossils of the Upper Chalk (higher zones') 



Porifera. Cceloptychium agaricioides, Plinthosella squamraosa, 



Scytalia radiciformis, Siphonia Kcenigi, Stichophyma 

 tumidum. 



Anthozoa. Caryophyllia cylindracea, Ccelosmilia laxa, Parasmilia 



Fittoni. 



Echinoderma. Galerites ( = Echinoconus) abbreviatus, Offaster pilula, 

 Marsupites testudinarius, Micraster coranguinum, 

 Cardiaster ananchytis. 



Brachiopoda. Rliynchonella limbata, Magas pumilus, Crania costata, 

 Terebratulina Rowei, T. gracilis. 



Lamellibranchia. Ostrea acutirostris, 0. curvirostris, 0. lunata, 0. 

 wegmaniana, Pecten Nilssoni, P. cretosus, P. 

 Mantellianus, Spondylus dutempleanus. 



Cephalopoda. Haploceras leptophyllum, Scaphites constrictus, Bacu- 

 lites Faujasi, Hamitea cylindraceus, Actinocamax 

 quadratus, Act. granulatus, Belemnitella mucronata, 

 B. lanceolata. 



Besides the above, the following are more or less common 

 throughout the Upper Chalk : 

 Porifera. Heterostinia obliqua, Ventriculites decurrens, V. 



radiatus. 



Anthozoa. Parasmilia centralis, Axogaster cretacea. 



Echinoderma. Echinocorys ( = Ananchytes) vulgaris, Galerites (Echino- 



conus) conicus, Cidaris sceptrifera, Phymosoma 



( = Cyphosoma) Koenigi. 

 Brachiopoda. Terebratula carnea, Rliynchonella plicatilis, Rh. 



reedensis. 

 Lamellibranchia. Ostrea semiplana, Spondylus spinosus. 



C. THE UPPER CRETACEOUS OF BRITAIN 

 1. England 



In describing the Upper Cretaceous strata it will be more 

 convenient to take each stage separately and trace its variations 

 across England. 



Selbornian. This stage includes the deposits which have long 

 been known as Gault and Upper Greensand, names which date from 

 a time when a Middle Cretaceous Series was supposed to exist, 

 comprising the Lower Greensand, the Gault, and the Upper Green- 



2K 



