16 



THE LIAS AMMONITES. 



Section of the Zone of Aegoceras planorbis, at Street, Somerset. 



LiTHOLOGY AND LoCAL NaMES OF BeDS. 



Thick- 

 ness. 



Organic Remains. 



14 



IG 



17 



24 



25 



26 



Light-coloured marly clay. "Top Bed" 



Light-coloured Lias limestone 



Yisllowish laminated, shale, splitting up 



into thin layers 



Light-coloured shaly limestone 



Hard grey limestone. '' Building-stone " 



Dark -grey shale 



Dark-grey limestone. "Corn-sized build- 

 ing-stone " 



OSTKEA SeEIES. 



Dark laminated shale 



Dark-grey limestone. " Five-inch build- 

 ing-stone " 



Dark shale 



Dark-grey limestone. " Six-inch build- 

 ing stone " 



Dark shale 



Greyish hard limestone. " The Whet- 

 stones." Best paving-bed. Consisting 

 of two 4-incli beds 



Hard dark marl. " Saurian bed " 



Greyish fine-grained limestone. "The 

 Cream-bed." Fine-grained paving- 

 stone 



Brownish limestone. " Red Liver." 

 Paving-stone 



Dark-coloured limestone. " The Black 

 stone," used for large paving-slabs ; 

 some of them 10 ft. by 5 ft 



Dark-blue shale 



Hard greyish limestone. " Six-inch 

 building-stone " 



Soft bluish shale 



Greyish-blue limestone. " Four-inch 

 building-stone " 



Dark-gray laminated shale 



Hard blue limestone. "The Blue Clog," 

 or " One-foot building-stone," used 

 for steps 



Grey laminated shale 



ft. in. 

 3 

 9 



3 

 4 



3 



6 



4 



Greyii-h limestone. "Grey Clog." A 

 valuable building-stone, used for steps, 

 troughs, &c 



Dark shale 







3 







4 







4 







2 







6 







2 







4 







4 



1 







1 



3 



PliANOKBIS SeBIES. 



Saurian bones and Aegoceras planorbis. 



Aegoceras planorbis in moulds. 



Ichthyosaurus intermedms, Aegoceras 2}lano?'bis, 



Lima punctata, and Isastrtsa Murchisoni. 

 Aegoceras planorbis, compressed. 

 Aegoceras planorbis, on the top of the bed, Lima 



punctata and Lima gigantea. 

 Aegoceras planorbis and muricated. spines of 



Cidaris Edwardsi. 

 Spines of Cidaris and bones of Ichthyosaurus 



OsTREA Series. 



Ostrea liassica. 



1 



2 



Ostrea liassica. 

 Ostrea liassica. 



Gardinia crassiuscula, Lima punctata, and Ostrea 

 liassica. 



Fossils rare : Ostrea liassica and Modiola minima. 



Many Saurians have been obtained from this bed. 

 Ichthyosaui-us intermedius and Plesiosaurus 

 Hawhinsii (British Museum). Many jaws of 

 Saurians and Fishes. 



Ostrea liassica and Modiola minima. 



Few fossils. 



Modiola minima, Ostrea liassica, Pleuromya, and 



Rhynchonella variabilis. 

 Ostrea liassica and Modiola minima. 



Ceromya, sp., Modiola minima, and Ostrea liassica. 



Fossils as in No. 19. 



Ichthyosaurus intermedius and I. tenuirostris. 



Ceromya, sp., Ostrea, Modiola, and Rhynchonella. 



Saurians abundant : Ichthyosawus intermedius 



and I. tenuirostris, Fholidophorus leptoceplialus. 



Modiola minima. 



