48 



THE LIAS AMMONITES. 



Dorsetshire. — At Lyme Regis the Bucklandi series is overlain by thick beds of clay 

 and slaty marls containing many Enaliosaurian skeletons, with numerous Fishes, in fine 

 preservation ; these strata are known to local collectors as the Fish- and Saurian-beds. 

 The magnificent specimen of Ichthyosaurus plalyodon, Conyb., now in the British Museum, 

 came from this clay, as proved by the impressions of Arietites semicostatus seen on the 

 matrix. This thick clay-bed is underlain by a thin band of greyish-limestone, in which 

 Ar. Turneri is found. The following section at Lyme Regis shows the sequence of the 

 Turneri beds at that locality in a descending order. 



Section of the Zone of Arietites Turneri at Lyme Regis. 



•££ 



m 



No. 



LlTHOLOGY. 



Thick- 

 ness. 



i 

 Organic Remains. 



1 



2 



3 



4 



Thick limestone, " Broad Ledge " 

 Black shales, with bands of brown clay. 

 "Saurian- and Fish-bed" 



ft. in. 

 3 6 



18 

 4 



3 



Ichthyosaurus jilatyodon, Conyb., /. com- 

 munis, Conyb., Arietites semicostatus, 

 Ar. Turneri, Sow., and Fishes. 



Arietites Turneri, Sow., and Ar. semi- 

 costatus, Young and Bird. 



Lima gigantea, Sow., L. antiquata, Sow., 

 and Rhynchonella variabilis, Schloth. 



Greyish, hard, shelly limestone 



Dark shales, with indurated bands of 



imperfect limestone 



Greyish limestone 





Beds with Arietites Bucklandi and Lima gigantea. (See p. 38.) 



Fossils of the Zone of Arietites Turneri. 1 



Ichthyosaurus platyodon, Conyb. 

 Museum). 



— intermedius, Conyb. 



wick Museum). 



— communis, Conyb. 



Museum). 

 Arietites Turneri, Sow. 



— semicostatus, Young fy Bird. 



— Bonnardi, iTOrb. 

 Turbo solarium, Piette. 

 Lima punctata, Sow. 



— gigantea, Sow. 



— pectinoides, Sow. 



(British 



(War- 



(British 



Cardinia ovalis, Siutch. 

 Ostrea Goldfussii, Bronn. 

 Avicula insequivalvis, Sow. 

 Pecten textorius, Schloth. 



— glaber, Hehl. 

 Astarte obsoleta, Dunk. 

 Crenatula, nov. sp. 

 Plicatula spinosa, Soiv. 

 Gervillia Hagenovii, Dunk. 

 Gryphsea arcuata, Lamk. 

 Cidaris Edwardsii, Wr. 

 Pseudodiadema spines. 

 Pentacrinus tuberculatus, Miller. 



1 I have omitted the Lias Fishes found at Lyme Regis, as there is some doubt about the beds from 

 which the different species were collected ; a large majority of them, however, I believe, were obtained from 

 this zone of life. 



