22 
D. Lias Series. 
6. Lias Stokesley, Guisbro’, Easingwold. 
E. Oolite Series. 
7. Bath Oolite Whitby, Scarbro’, and the summit 
of the eastern moorlands. 
8. Oxford Oolite ILelmsley, Malton. 
9. Kimmeridge clay Pickering, Kirby Moorside. 
These strata have been many times elevated and depressed during the 
period of their deposition : and a considerable portion of them must even 
have been submerged since various members of the flora and fauna of 
the county have occupied the regions which they now inhabit. The 
prominent physical features which we observe have been gradually de- 
veloped through the long succession of ages by the continual action of 
water upon the surface. So that the strata formed of softer materials, 
the sandstones and aluminaceous shales have wasted away beneath its 
abrading influence, and now form the central vale and lower levels of the 
county : whilst the oolites and still harder gritstones have better with- 
stood its power, and now tower upwards as ranges of hills and moorlands 
of greater or lesser elevation, margined by “grey cliffs and winding scars.’’ 
As may be seen at a glance by reference to the map, the three vice- 
counties of the “Cybele Britannica” which are wholly or partially included 
in the north riding, may be conveniently subdivided into eight districts, 
founded upon the river drainage. Of these, North-east Yorkshire will 
comprise five, North-west Yorkshire two, and Mid-west Yorkshire one- 
If we also include the Ainsty, the vice-counties will contain respectively 
five, two, and two districts, as below : — 
Name oe District. 
Vice -county No. I. North-east York. 
District 1. Ouse and Foss 
2. East Swale 
3. Derwent 
4. Esk 
5. East Tees 
Yice-county No. II. Mid-west York. 
6. Nidd and Wharf (Ainsty) 
7. Ure 
Vice-county No. III. North-west York. 
8. West Swale 
9. West Tees 
Area in Square Miles. 
133 
165 
514 
235 
147 
1194 
84 
259 
343 
364 
186 
550 
2087 
