1857.] NICOL — LOCH GREINORD. 167 



EXPLANATION OF PLATE XI 



Fig. 1. Palaoniscus superstes (from Rowington, Warwickshire), natural size. 



Fig. 2. Ditto. Counterpart of the same. 



Fig. 3. Anal fin, enlarged 4 times. 



Fig. 4. Palceoniscus catopterus, from Roan Hill, Tyrone. 



7. On the Newer Red Sandstone, and on some other Geolo- 

 gical Phenomena, near Loch Greinord, in Ross-shire. 

 By James Nicol, F.R.S.E., F.G.S., Professor of Natural History, 

 Aberdeen. 



Newer Red Sandstone. — In several passages of his work on the 

 Western Isles, Dr. Macculloch refers to the occurrence on the shores 

 of Loch Greinord of two small spots of a red sandstone of newer age 

 than the great mass of similarly coloured rock which forms so con- 

 spicuous a feature on the western coasts of the Highlands*. In his 

 memoir on the Geological Map of Scotland he also several times 

 mentions this formationf , which he considered as the only undoubted 

 instance of the occurrence of the " Red Marl" of English geologists 

 in the northern part of the island. Although evidently regarding 

 these beds with much interest, he has not given any detailed descrip- 

 tion of them. In their valuable memoir on the formations in the 

 North of Scotland, Professor Sedgwick and Sir Roderick I. Mur- 

 chison likewise mentioned this deposit, and pointed out its resem- 

 blance to the New Red of England, and also to some beds seen 

 below the Lias in SkyeJ. This sandstone does not seem to have 

 been subsequently noticed by geologists, probably from lying in a 

 region so seldom visited by the scientific traveller. I have therefore 

 been induced to lay before the Society the following notes collected 

 in an examination of this deposit in the autumn of last year (1856). 



The great headland of the Ruimore or Ru Rea that separates Loch 

 Greinord from Loch Ewe consists chiefly of the older red sandstone 

 of the west coast, covered more or less deeply by drift or detritus. 

 On the shore of Lake Greinord the sandstone is well seen in thick, 

 undulating, or slightly curved beds, dipping at 40°-45° to E. 5°— 

 10° S. It is usually a fine-grained grit, of a reddish-brown colour, 

 occasionally with a tinge of green, but becomes black when weathered. 

 As this rock was fully described in my paper on the Red Sandstones 

 of the North-west coast of Scotland, its mineral characters need not 

 be noticed further §. Near Sands andUdrigill, the newer sandstone 



* Macculloch's Western Isles, vol. ii. pp. 65, 99. 



f Memoir on Map, pp. 31, 89, 94. 



X Transact. Geol. Soc, New Series, vol. iii. p. 156. 



§ Quarterly Journal of the Geological Society, vol. xiii. p. 17. In that memoir 

 I considered this red sandstone as probably of Devonian age, or the equivalent 

 of the true " Old Red" of other parts of Scotland. In the present paper, however, 

 1 have generally designated it only as the " Older Red Sandstone," in contra- 

 distinction to the " Newer Red" resting on it ; thus avoiding any assumption in 

 regard to its age. Sir R. I. Murchison, however, regards it as the representative 

 of the Cambrian of Wales. 



