406 Geological Society. 



Chalk. Bay, Sussex, associated with Venericardia 

 planicosta, and other London clay shells. 



9. Variegated sands 10 paces. 



10. Dark greenish gray sand and clay like No. 8. 54 — 



11. Variegated sands like those of Alum Bay. ... 38 — 



12. Greenish gray, hrown, and greenish brown"! ,„ 



clays / ^"^ ~~ 



This bed contains lignite, sharks' teeth. 

 Valuta luctator, Ostrea, and numerous other 

 shells characteristic of the London Clay. 



13. Yellowish sandy clay, without fossils 26 — 



14. Greenish sand similar to that of the upper ^ 



marine in Colwell Bay, and containing ap- V 12 — 

 parently the same Venus J 



15. Yellowish sand without fossils 14 — 



Beyond this point, freshwater beds, enclosing abundance of Po- 



tamides, are displayed. 



The above section proves, in Mr. Bowerbank's opinion, that in 

 White Cliff Bay there is an alternation of London and plastic clays 

 throughout 525 paces, and that London clay fossils not only occur 

 abundantly in the part which corresponds with the great mass of 

 that formation in Alum Bay, but are likewise found in the beds, 

 Nos. 8. and 6, which occur below it. 



Mr. Bowerbank then described the strata in Alum Bay, taking 

 Mr. Webster's section as the base of his observations ; and he 

 pointed out, that in the beds of greenish gray sand and clay marked 

 d in that section, and below the variegated sand and clays which 

 underlie the London clay, he found the following shells, charac- 

 teristic of that formation : — Venericardia planicosta, Cardita marga- 

 ritacea, Mya intermedia, Cardium semigranulatum, Nucula similis, 

 N. amygdaloides, Turritella conoidea, T. elongata, T. edita, Murex 

 innexus, (Brander) Buccinum desertum, and Cancer Leachii. In the 

 variegated sands and clays no fossils were found. 



An extract from a letter, dated Newcastle, 14th February, 1839, 

 and addressed to Dr. Buckland, by Mr. Atkinson, was then read. 



This letter accompanied a series of slabs of fissile or slaty mica- 

 ceous sandstone, presenting the tortuous casts of vermiform bodies, 

 either impressed in the stone or in relief. The more perfect casts 

 are marked by a longitudinal line, and closely-set transverse fine 

 striae. The bed from which the slabs were procured, belongs to the 

 carboniferous formation near Haltwhistle in Northumberland. 



The following is the succession of strata presented by the quarry : 



Compact sandstone 



Red marly sandstone, with shells 10 inches. 



Micaceous blue and white sandstone, containing"] 

 the casts, the largest of which are found near the I i n r 

 centre of the bed. The stone splits into thin T 

 flags, and is used for roofing J 



Compact sandstone 30 — 



liimestone containing in one part a few encrinitsd \ „^ 



remains 



/ 



