DAVIS ! SECTIONS IN THE LIASSIC AND OOLITIC ROCKS OF YORKSHIRE. 201 
along the shore at Gristhorpe. The series forms the base, and 
extends far up the face of the cliff, gradually dipping to the south- 
east towards Cun stone Nab, where it disappears beneath the Corn- 
brash, the uppermost bed of the Lower Oolites, and the Kelloways of 
the Middle Oolites. 
The Cornbrash, though a comparatively thin rock, being only a 
few feet in thickness, is a very persistent one, and highly charged 
with fossils. Its base is a rubbly limestone with a grey colour, 
occasionally oolitic or ferruginous ; above this are about 6 feet of 
shales, finely laminated and bluish grey in colour, containing Avicula 
echinata, Gryphcea stricklandi, and other fossils. The blue colour of 
the shales and ferruginous aspect of the limestone are useful in tracing 
the beds. The shale or " Clays of the Cornbrash " as they are some- 
times termed pass gradually up into the yellow argillaceous base of 
the Kelloways Rock. 
The Cornbrash first makes its appearance at the base of the 
cliff at Wyke, an indent of the coast south-east of Gristhorpe Bay ; 
and may be traced, if not hidden by the debris of the stupendous 
cliffs above, along the Gristhorpe cliffs for some distance. At Red- 
cliffe it is thrown down by the fault, and appears on the shore a little 
below high water mark. (Fig. 7.) It is very fossiliferous, the following- 
list representing some of the most characteristic : — 
Echinobrissus orbicularis, Phil. Avicula echinata, Sow. 
Holectypus depressus, Lam. Pinna cuneata, Bean. 
Rhynchonella concinna, Sow. Modiola cuneata, Sow. 
Waldheimiala obovata, Sow. Trigonia Scarburgensis, Lyc. 
W. ornithocephala, Sow. T. elongata, Sow. 
Ostrea flabelloides, Lam. T. cassiope, D'orb. 
Pec ten lens, Sow. Cardium cognatum, Phil. 
P. demissus, Phil. Unicardium depressum, Phil. 
P. vagans, Sow. Pholadomya angustata, Sow. 
Lima duplicata, Sow. Homomya crassiuscula, Lyc. & Mor. 
Goniomya v. scripta, Sow. Bulla undulata, Bean. 
Myacites decurtata, Phil. Chemnitzia vittata, Phil. 
Gresslya peregrina, Phil. Littorina punctura, Bean. 
Actasonina Scarburgensis, Lyc. Ammonites Herveyi, Sow. 
Amberlya armigera, Lyc. 
