398 PEOCEEDnfGS OF THE GEOLOGICAL SOCLETY. [DeC. 1, 



conglomerate assumes in various hills where it rises in more or less 

 rounded pyramidal masses, which have been embossed as it were on 

 the edges of the crystalline rocks. Good examples of this are given 

 in the fly-flap of the coloured section given by Sedgwick and myself, 

 where the Maiden Pap and Morven rise above the adjacent quartz- 

 rocks, and again where the hill of Meal Turach stands out in Eoss- 

 shire above the gneissose rocks of Loch Glas, at the foot of Wyvis*. 

 The hill of Ben-a-vraggie, above Dunrobin in Sutherlandshire, on 

 which the monument of the late Duke of Sutherland stands, is also 

 a striking example of these lower conglomerates. 



At Skibo Castle, the seat of my friend Mr. Dempster, a deep- 

 red coloured sandstone has been opened out in the lower division of 

 the formation, the strata of which dip away from the slopes of gneiss- 

 ose hills to the Dornoch Firth ; and in this sandstone Miss Demp- 

 ster procured two incurvated casts about 8 or 9 inches long, which, 

 terminating in points, rudely resemble, the pincers of a huge Crusta- 

 cean. If these casts should prove to be referable to some such creature 

 as the Pterygotus of Herefordshire, Shropshire, Forfarshire, &c., they 

 stand as yet alone as indications of animal life in the Lower Old Red 

 of the North-east of Scotland. 



In this vicinity and in the much higher beds which shelve away 

 on the coast near Embo with an easterly dip, the sandstones become 

 more yellow, and range along the shore to the town of Dornoch. 

 Near Embo they contain strong pebbly beds, and are marked by 

 blotches of deep-red shale, occasionally circular. In these same 

 beds and among the pebbles which have been chiefly derived 

 from the crystalline rocks of the interior, Mr. Peach and myself 

 detected some fragments of those cherty and very peculiar beds of 

 the Durness and Assynt limestone, as well as portions of quartz-rock. 

 In following these upper ledges from Embo to Dornoch, the rock is 

 well exposed in quarries which have been opened for the construction 

 of the new buildings in the town ; and the yellow and even whitish- 

 coloured sandstone there predominates over the deep-red, the latter 

 being thrown away as refuse. Now, as these light-yellow strata 

 with occasional pebbly beds are inclined gently to the S.S.E., they 

 (as well as the sandstones of Tain and Tarbet Ness) seem to form 

 the north-western side of a wide basin, the south-eastern side of 

 which reappears on the opposite side of the Moray Firth, near Elgin, 

 where similar yellow sandstones occur. 



In Ross-shire, the quartzose micaceous schists and gneiss through 

 which the Rivers Connan and Orron flow from the central highlands 

 and the mountains of Strath Connan and Strath-glas, have the pre- 

 valent dip to the E.S.E., and are admirably exposed on the banks of 

 both those rivers, just where they issue to the low tract of Easter 

 Ross. At no spot is the unconformity between these crystalline 

 rocks and the Old Red Sandstone better seen than to the west of the 

 ancient Tower of Fairburnf, where a feeder of the Orron flows over 



* Trans. G-eol. Soc. Lond. 2nd ser. vol. iii. pi. 14. figs. 3 & 5. 

 t The seat of the Mackenzies of Fairburn, my maternal ancestors, who 

 possessed the estates of Fairburn, Strath Connan, and Monar. 



