440 F. G. H. PRICE ON THE BEDS BETWEEN THE 



the Holaster-subglobosus sea-period, but was not widely distributed. 

 At the time of the invasion of the Turonian sea the Upper Cenomanian 

 beds were more or less denuded; and the Belemnites plenus which 

 they contained were found rolled, remanies at the base of the Turo- 

 nian ; they are very abundant there, and form, without doubt, the 

 zone of Belemnites jplenus of M. Hebert. 



It will be seen from my table that this bed is classed as the top 

 bed of the Grey Chalk, which, together with the Chalk Marl at Lyd- 

 den Spout, has a thickness of 197 feet, including beds from I. to VII. 

 Hippurites or Radiolites Mortoni appears in this zone, and extends to 

 the base of the Upper Chalk. The palates of Ptychodus are, in this 

 band, of a yellow colour ; whilst in the other beds of the Grey Chalk, 

 already described, they are darker and almost black. Mr. Whitaker 

 likewise considers this bed the top of the Grey Chalk or Chalk Marl. 



There are very few fossils in this bed ; the following have been 

 met with : — 



Plicatula inflata (which does not go up 



higher). 

 Belemnites plenus. 



Ptychodus decurrens. 

 polygyrus. 



This bed is the Belemnites-plenus zone. 



Bed VIII. (Lower Chalk). 



This bed is about 32 feet thick, and consists of exceedingly hard 

 gritty chalk, made up of comminuted fragments of Inocerami and 

 other fossils. 



This bed, called the " grit bed," is very readily distinguished from 

 the other zones, as it may be traced for a long distance along the 

 cliffs from Folkestone to Dover above the Warren, standing out be- 

 yond the softer beds above and below. The chalk of this bed is so 

 hard as to turn the point of the pick-axe. 



At the lower portion of this bed Discoidea minima (?) is found in 

 large quantities, succeeded by Echinoconus subrotundus, which is only 

 found in that particular line in this bed, it never being met with 

 either above or below it. 



Ptychodus decurrens is small in this bed, and in the lower part of 

 it is of a light colour, as in bed VII. ; in the higher part of the bed 

 the specimens become darker and larger. 



Beds VIII. and IX. I consider to be Lower Chalk. They repre- 

 sent the "Turonien " of D'Orbigny and the Inoceramus-labiatus zone 

 of Dr. Barrois, with whose classification of these beds I entirely 

 agree, as here in bed VIII. the Inoceramus labiatus makes its first 

 appearance, continuing through bed IX. to the Upper Chalk. 



This bed, together with about 43 feet of my next bed, form 

 what Mr. Drew, in Whitaker's ' Memoir,' calls concretionary? (no- 

 dular) chalk. 



A few fossils appear to be peculiar to this bed, and they are 

 as under : — 



