UPPER OLD RED SANDSTONE. I43 



An excellent section of the transition beds from the Upper Old 

 Red Sandstone to the Carboniferous Limestone has been exposed 

 near the Hawthorns, in the "Deep Cutting" of the road from Ross 

 to Drybrook in the Forest of Dean.^ 



At Farlow, between Brown Clee Hill and Cleobury Mortimer, in 

 Shropshire, the yellow sandstones quarried for building-purposes 

 have yielded palatal teeth of fishes and other interesting fossils. A 

 Pterichthys-bed with P. macrocephnlus was noticed by Prof. J. Morris 

 and Mr. G. E. Roberts.^ Remains of Holoptychius and Conularia 

 have also been found at this locality. The Farlow sandstones and 

 pebble-beds appear to belong to the passage-beds between the Old 

 Red Sandstone and Carboniferous rocks ; and they are famous as 

 having yielded the remains of fishes which characterize the 

 celebrated beds of Dura Den in Fife, Scotland.^ 



The Old Red Sandstone of Portishead, near Bristol, consists of 

 red sandstone, marl, and conglomerate, with a Fish-bed yielding 

 Holoptychius and Coccosteus. This bed was discovered by the Rev. 

 B. Blenkiron.* 



The denudation of the Mendip Hills has exposed the Old Red 

 Sandstone in several tracts, the most easterly exposure is about a 

 mile north of Frome : westwards it is most prominent at Black 

 Down, and may be seen also near Winscombe. (See Fig. 24.) 



Beds of red conglomerate and sandstone belonging to the Upper 

 Old Red Sandstone occur in the Lake District : they rest uncon- 

 formably upon the Cambrian and Silurian rocks, and indeed contain 

 pebbles with Cambrian and Silurian fossils. The beds are over- 

 laid conformably by the Carboniferous Limestone Series, and 

 according to Sedgwick, beds of red sandstone, of similar type to 

 that of the Old Red Sandstone, alternate in thick masses with the 

 limestone. The Old Red Sandstone, or rather conglomerate, is 

 very variable in thickness ; it is stated by Mr. J. G. Goodchild to 

 attain a thickness of from 1000 to 1200 feet in the Ulleswater area, 

 from 900 to 1000 feet near Melmerby, beneath the Pennine Chain, 

 and 1000 feet or more near Sedbergh. Professor Harkness con- 

 siders its thickness near Shap to be 270 feet, while near Lowther 

 it is not more than 40 or 50 feet, and under Ingleborough it is 

 almost entirely unrepresented. These beds, sometimes grouped 

 as Basement (Carboniferous) conglomerate, may be seen at Great 

 Mell Fell, south of Troutbeck railway-station. 



In the Cheviot District the Upper Old Red Sandstone rests un- 

 conformably on the Cheviot Volcanic Series. (See Fig. 16, p. 1 14.) 

 The series consists of the following divisions : — 



3. White and red sandstones. 



2. Red earthy beds. 



I. Conglomerates (local). 



^ John Jones and W. C. Lucy, Proc. Cotteswold Club, 1857, p. 175. 

 ^ Q. J. xviii. 95. 



Symonds, Records of the Rocks, p 250. 

 * Proc. Bristol Nat. Soc. ii. 79. See also Dr. S. Martyn, ser. 2, vol. i. p. 141. 



