232 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 22, 



E. Belemnites semicanaliculatus ?, 

 Blainv. 



E.. jaculum, Phil. 



E. , sp. 



B. Middle Neocomian. — The second division of the Speeton Clay- 

 is seen lying immediately below the " Cement-beds," in the northern 

 part of Black Cliff and the southern part of Middle Cliff. On the 

 spur between these two cliffs, which affords special facilities for their 

 study, the beds of this division are found to extend from a height 

 of 20 feet up to 170 feet above high- water mark, and are therefore 

 about 150 feet thick. 



Directly below the ^' Cement-beds " we find a great thickness 

 (80 feet) of dark- blue clays, containing but few septaria, and these 

 apparently not occurring in definite layers. Throughout this bed 

 fossils are extremely rare. They are of the following species :^ 



r. Vermicularia PhUlipsii, Eom. sp. 

 r. Pecten cinctus, Sow. (large form), 

 r, Exogyra sinuata, Sow. (typical 

 form). 



These beds are underlain by others of similar lithological cha- 

 racter but much more fossihierous, which are about 40 feet thick ; 

 they are characterized by the great abundance of the gigantic form 

 of Pecten cinctus, of Exoyyra sinuata (the typical form, often of 

 great size), and of Belemnites jaculum. Owing to the circumstance 

 of their being enclosed in clay, it is rarely that we find perfect 

 specimens of the Exogyroe and Pectines, though their fragments are 

 extremely numerous. 



In the lower part of this mass of clay there occur several layers 

 of small dark-brown nodules with pyritous septa. In one of these 

 seams almost every nodule contains a specimen, more or less perfect, 

 of the Meyeria ornata, Phil. sp. This is the " Shrimp-bed" of 

 collectors. In larger scattered nodules in the same portion of the 

 bed there occur specimens of a large undescribed Ammonite {A. 

 bipinnatus, Will. MS.) and of Ancyloceras Duvalii, Leveille. This 

 portion of the series may be well studied in Middle Cliff, and also in 

 New Closes Cliff, where it is brought down by a landslip. 



The base of the second division of the Speeton Clay is formed by 

 a bed of dark-blue clay, distinguished by containing regular layers 

 of septaria, which are of a light-brown colour, and contain specimens 

 of Ancyloceras and Ammonites. As this is the horizon at which the 

 former fossils attain their maximum of abundance, we may appro- 

 priately call this bed " the Ancyloceras-bed." It is likewise the 

 metropolis of Belemnites jaculum. 



Fossils from tJie Middle Neocomian of Sjpeeton. 



Ammonites cryptoceras, jD' Orb. 



crassicostatus, VOrh. 



angulicostatus, IP Orb. 



Ancyloceras (Crioceras) Duvalii, 



Leveille. 

 (Crioceras) Emericii, Leveille. 



' ^.P- 



Meyeria ornata, Phil. sp. 



Other crustacean remains. 



Cerithium Phillipsii, Leym. 



T. 



Vertebras and teeth of fishes. 



E. 



E. 



Belemnites semicanaliculatus ?, 



E. 





Blainv. 



E. 



r. 



, sp. 



C. 



C. 



jaculum, Phil. 





c. 



Ammonites bipinnatus, WiU. MS. 



C. 



c. 



marginatus, Phil. 



r. 



r. 



nucleus, Phil. 



C. 



T. 



Nisus, i)'0r6. 



r. 



c. 



— — rotula, Sow. 



r. 



