388 



STRATIGRAPHICAL GEOLOGY 



Gastropoda. Pleurotomaria anglica, Crypteenia expansa, Amberleya 

 elegans. 



Cephalopoda. The following Ammonites characterise zones or sub-zones 

 in ascending order : Psiloceras planorbe, Schlotheimia 

 angulata, Coroniceras Bucklandi, Arnioceras semi- 

 costatum, Arietites Turneri, Asteroceras obtusum, 

 Oxynoticeras oxynotum, Echioceras raricostatum, 



g 



Fig. 125. OKOUP OF RHjETIC FOSSILS. 



a. Protocardium rhseticum. </. Myoplioria postera. 



b. Pecten valoniensis. e. Orbiculoidca Townshendi. 



c. Pteria contorta. / Ceratcdus parvus. 



i], Nemacanthus monilifer. 



Deroceras armatum, Uptonia Jamesoni, Rhacoceras* 

 ibex, ^Egoceras capricornus, Nautilus striatus, 

 Belemnites acutus, B. elongatus, B. clavatus. 



Pisces. Dapedius punctatus, Hybodus reticulatus, Acrodus 



Anningse. 



Heptilia. Ichthyosaurus communis, Plesiosaurus dolichodeirus. 



Fossils of the Middle Lias 



Echinoderma. Ophioderma Egertoni, 0. Milleri. 



Brachiopoda. Rhynchonella tetrahedra, R. acuta, Terebratula punctata, 



Waldheimia (Aulacothyris) resupinata, Waldheimia- 



(Zeilleria) cornuta. 



