226 TROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 22, 



meros, and are of but few species. These clays are about 50 feet 

 thick, and contain a few scattered septaria, of small size, composed 

 of argillaceous ironstone of a pale-brown colour, and having extremely 

 thin septa composed of crystallized pyrites. The small number of 

 species of fossils occurring in this bed are all common to it and the 

 bed below. They are as follows : — 



C* Belemnites semicanaliculatus 



{Blain. ?). 

 c. Belemnites minimus, List. 



c. Vermicularia PhHlipsii, Edm. sp. 



r. Alaria (?), sp. 



r, Ehynchonella sulcata, Park. 



The base of the highest division of the Speeton Clay is formed 

 by the well-marked band known to the workmen as the " Cement- 

 bed." It consists of a very light-blue clay, of great tenacity, and 

 containing regular layers of large septaria. These sei)taria are com- 

 posed of argillaceous limestone, of a very pale, almost white colour, 

 with thick septa of calcspar. The contrast between this light- 

 coloured band and the darker beds above and below it is very striking. 

 The Cement-bed is well seen in the cliff, and can be easily traced 

 by the old workings from Speeton Gap, where its base is between 

 20 and 30 feet above high-water mark, to the place of its outcrop 

 near the northern extremity of Black Cliff. It is also well seen in 

 the landslip at the base of the same cliff. Both the septaria and the 

 clay of the Cement-bed are of considerable commercial value. ( Fide 

 Appendix C.) 



This bed is crowded with fossils, which occur either mineralized 

 by pyrites and scattered through the clay, or enclosed in and re- 

 placed by the substance of the septaria. Some of the fossils attain 

 a great size, as the large and nearly smooth species of Ammonites 

 (undescribed), and the so-called Hamites maximus (probably an 

 Ancyloceras) ; on one occasion I had an opportunity of seeing an 

 Ammonite (probably of a new species), imbedded in the soft clay 

 and incapable of removal, which measured three feet in diameter. 



The total thickness of the highest division of the Speeton Clay is 

 certainly considerably above 100 feet. Its fauna, as will be seen 

 from the subjoined list, is most unmistakeably that of the Lower 

 Greensand and Atherfield Clay of the south of England. 



Fossils of the Upper Neocomian of Speeton. 



r. Plesiosaurus (vertebrae and paddle- 

 bones). 

 E,. Teleosaurus (skull). 

 c. Teeth of Lamna. 

 c. Vertebrae and other remains of 



C. Belemnites semicanaliculatus 

 {Blain.'}). 



c. minimus ?, List. 



c. ultimus ?, jD' Orb. 



C. Ammonites Deshayesii, Leym. 



E-. ■ , var. curvinodus, Phil. 



R. Obscure crustacean remains. c. Nisus, 2>' Orb. 



? Meyeria Vectensis. c. nucleus, Phil. 



R. Plate of Cirripede. c. marginatus, Phil. 



R. Nautilus pseudo-elegans, D' Orb. r. rotula, Sow. 



r. radiatus, Sovj. \ C. (spec. nov?). 



r. plicatus, &w. i R. spec, no v. 



* Throughout this paper the letters affixed to the species indicate their rela- 

 tive abundance in the bed : c signifying co'iimon, C very common, r somewhat 

 rare, and R very rare. 



