THE BRITISH REPTILES. 127 



VIPERIDM. 

 81. Vipera berus (Forest Bed and Existent), Viper. 



PYTHONID.E. 



Paleryx depressus (Upper Eocene). 

 Paleryx rhombifer (Upper Eocene). 



PAL&OPHID&. 



Palaeophis longus (Lower Eocene). 

 Palaeophis toliapicus (Lower Eocene). 

 Palaeophis typhaeus (Lower Eocene). 



MOSASAURID^E. 



Leiodon anceps (Upper Chalk). 



Platecarpus (Chalk). 



Mosasaurus (Chalk). 



Patricosaurus merocratus (Cambridge Greensand). 



ICTHYOSAURIA. 



ICTHYOSA URID&. 



Baptanodon cantabrigiensis (Cambridge Greensand), 

 Ophthalmosaurus icenicus (Oxford Clay and Kime- 



ridge Clay). 



Icthyosaurus acutirostris (Upper Lias). 

 Icthyosaurus asqualis (Kimeridge Clay). 

 Icthyosaurus breviceps (Lower Lias). 

 Icthyosaurus campylodon (Cretaceous). 

 Icthyosaurus communis (Lower Lias). 

 Icthyosaurus coniformis (Lower Lias). 

 Icthyosaurus conybearei (Lower Lias). 

 Icthyosaurus dilatatus (Oxford Clay). 

 Icthyosaurus entheciodon (Oxford Clay and Kime 



ridge Clay). 



Icthyosaurus intermedius (Lower Lias). 

 Icthyosaurus latifrons (Lower Lias). 

 Icthyosaurus megalodeirus (Oxford Clay). 

 Icthyosaurus ovalis (Kimeridge Clay). 

 Icthyosaurus platyodon (Lower Lias). 

 Icthyosaurus tenuirostris (Lower Lias). 

 Icthyosaurus thyreospondylus (Kimeridge Clay). 

 Icthyosaurus trigonodon (Upper Lias). 

 Icthyosaurus trigonus (Kimeridge Clay). 

 Icthyosaurus zetlandicus (Upper Lias). 

 Cetarthrosaurus walkeri (Cambridge Greensand *< 



