ZONE OF AMMONITES TURNER!. 



71 



Saurian-beds. The magnificent specimen of Ichihyosaurm plafi/odoii, Conyb., now in the 

 British Museum, came from this clay, as is proved by the impressions of Am. semicostatiis, 

 Y. & B., which are seen on the matrix. This thick clay-bed is underlain by a thin band 

 of grayish-limestone, in which A)ii. Turneri is found. The following section of this zone 

 at Lyme Regis shows the sequence of the Am. Turneri beds at that locality. 



Section of tJie Zone 0/ Ammonites Turneri at Lyme Be/jis. 



LiTHOLOGY. 



Organic Remains. 



No. 



I" 1 'in. 



ft. in. 



1. Thick limestone, "Broad Ledge" 3 G Ichthyosaurus 'platyodon, Conyb., I. communis, 



2. Black shales, with bands of brown Conyb., Ammonites semicostatus, Am. Turneri, 

 ^ clay. Saurian- and Fish- Sow., and Fishes. 



^ s\ bed" 18 0 



3. Grayish, hard, shelly limestone ... 0 4 AmmonitesTurneri,^oyf.,andAm.se)nicostatus,Y.&B. 



4. Dark shales, with indurated bands 

 of imperfect limestone 3 0 



Grayish limestone Lima giyantea, Sow., L. antiquata. Sow., and 



Rhynchonella variahilis, Scliloth. 



Beds with Am. JBucMandi and Lima yigantea. (See p. 68.) 



CO 



Fossils of the Zone of Ammonites Turneri 



A 1 



Ichthyosaurus platyodon, Conyb, (British 

 Museum). 



— intermedius, Conyb. (War- 



wick Museum). 



— communis, Conyb. (British 



Museum). 

 Ammonites Turneri, Sow. 



— semicostatus, T. ^ B. 



— Bonnardi, d'Orh. 

 Turbo. 



Lima punctata, Soio. 



— gigantea, Sow. 



— pectinoides, Soiv. 



Cardinia ovalis, Stutch. 

 Ostrea. 



Avicula insequivalvis, Soiv. 

 Pecten textorius, SchJoth. 



— glaber, Hehl. 

 Astarte consobrina, Dewal. 

 Crenatula, nov. sp. 

 Plicatula spinosa. Sow. 

 Gervillia lanceolata, Sow. 

 Gryphsea incurva, Sow. 

 Cidaris Edwardsii, Wr. 

 Pseudodiadema spines. 

 Pentacrinus tuberculatus, Miller. 



1 I have omitted the fossil Fishes found in the Lias at Lyme Regis, as I was unsible to ascertain 

 with sufficient accuracy the beds from which the different species were collected ; a large majority of 

 them, however, I believe, came from this zone of life. 



