SPEETON CLAY. 
47 
About forty species only have yet been found in it, whilst thrice that 
number have rewarded the collectors in Norfolk, Wiltshire, Sussex, and 
Kent. 
CLIFFS OPPOSITE THE VALE OF PICKERING. 
From the termination of the white cliffs the coast bends to the 
northward, and exhibits in succession, rising from beneath the chalk, the 
Speeton clay and the coralline oolite series. The Speeton clay shews 
itself immediately in contact with the red chalk, so that there can be no 
question of its being the next subjacent stratum ; and therefore it will 
be useless to look for the greensand formation in this part of Yorkshire. 
The sand represented on Mr. Smith’s map of Yorkshire, as ranging on 
the south side of the vale of Pickering, is merely superficial : blue clay 
is found at too many points in contact with the bottom of the chalk, to 
leave the slightest doubt on the subject. At Speeton the clay is dark 
and laminated, with distant layers of nodules of argillaceous ironstone, 
the larger of which are fissured within, and have these fissures either 
empty, lined with crystals of selenite and iron pyrites, or filled up witli 
calcareous spar. Such large nodules occasionally contain ammonites and 
fragments of hamites. The smaller oval nodules frequently enclose small 
crustaceous animals, having the general appearance of the genus astacus, 
but with attenuated fore-legs, and slender sub-abdominal processes. A 
great number of very interesting fossils, which will be described here- 
after, have at different times been found in the clay at Speeton. Among 
the most curious, are a fragment of a jaw containing four rows of (molar) 
teeth in situ, in the possession of its discoverer, C. Preston, Esq. of 
Flashy, teeth and vertebrae of saurian animals, many beautiful ammo- 
nites, hamites, and nucuke, which ornament the cabinets of Mr. Bean and 
Mr. Williamson. To make any tolerable collection of the beautiful 
fossils of Speeton requires patience and assiduity ; for though they are 
really not scarce, yet it is only after rains have exposed a fresh surface 
that they can be found in plenty. 
