GAULT AND UPPER CHALK NEAR FOLKESTONE. 



435 



Bed II. (Chalk Marl). 



The chalk of this bed is very hard and coarse in texture and of a 

 light greyish colour, and is generally known as Chalk Marl, but, 

 owing to the presence of a few green grains near its base, has been 

 called by some geologists Chloritic Marl. 



It has a thickness of about 10 feet, and contains several hard bands 

 or reefs of sponges, notably of Plocoscyphia meandrina = Brachiolites 

 labrosus and Dendrospongia fenestralis, which do not occur otherwise 

 than iu these very hard bands. Occasionally these sponges are found 

 converted into iron pyrites. I measure this bed to the base of the 

 Grey Chalk, where these hard bands cease to be met with. 



Hard concretionary nodules, more or less incrusted with iron 

 pyrites, occur in this bed ; they bear every appearance of being much 

 rolled, and have Ostrece and Plicatulce adhering to them. 



The Chalk Marl is very fossiliferous ; the following is a list of 

 fossils obtained therefrom : — 



Plocoscyphia maeandrina (v. common). 



Dendrospongia fenestralis (common). 



Micrabacia coronula. 



Pollicipes glaber (rare). 



Cidaris vesiculosa. 



Holaster lsevis, var. nodulosus (com.). 



, var. trecensis. 



Serpula annulata. 

 Terebratula biplicata. 



obesa. 



Rhynchonella, sp. (crushed). 

 Inoceramus striatus (very common). 

 Lima globosa (common). 



parallela. 



, sp. 



Pecten Beaveri. 



campanensis. 



elongatus. 



orbicularis. 



Ostrea Irons, var. carinata. 

 Area fibrosa. 

 Natica, sp. 



Pleurotomaria perspectiva. 

 Solarium, sp. 

 Ammonites cenomanensis. 



falcatus. 



Mantelli. 



navicularis. * 



nothus, var. Mantelli. 



varians. 



Nautilus elegans. 



pseudo-elegans. 



Scaphites aequalis. 

 Turrilites costatus. 



Scheuchzerianus. 



tuberculatus. 



Edapbodon, sp. 

 Coprolites of fishes, &c. 

 Ichthyosaurus campylodon. 

 Saurocephalus lanciformis. 

 Acanthopholis horridus. 

 Wood. 



Janira quinquecostata. 

 Plicatula inflata (common). 



sigillina. 



Spondylus Dutempleanus. 



latus. 



Ostrea frons. 



It is remarkable that the remains of Ichthyosaurus are only met with 

 in the hard seams, which are mostly made up of sponges : it would 

 appear that the bones of these reptiles became entangled therein. 



Mr. Griffiths, of Folkestone, has told me that he has found in 

 this bed Ventriculites of large size, having a diameter of about six 

 inches across the cup, and weighing as much as 14 lb. 



This bed is equivalent to the Craie marneuse with Plocoscyphia 

 mceandrina of Dr. Barrois. 



The Chalk Marl (beds I. and II.) can be well examined in East- 

 Wear Bay, near that part known as the " Pelter." It passes gradu- 

 ally up into a more argillaceous marly chalk, generally termed Grey 

 Chalk. In order to see a fair section of this Grey Chalk, called the 

 " Assise du Holaster subglobosus " by Dr. Barrois, in his paper on the 

 zone of Belemnites plenus, it is necessary to go as far as Lydden 



