MALCOLMSON OLD RED SANDSTONE. 339 



sition of the Old Red Sandstone, by which different superior memberp. 

 of the system were placed in contact with the inferior roekvS ; and, 

 as this discovery ^rst afforded a key to the arrangement of these 

 strata, I shall describe them rather in the order in which the inquiry 

 was prosecuted than in the more approved method of a consecutive 

 descending series. 



The district over which the fossils have been discovered extends 

 from the village of Buckie, near Cullen, in Banffshire, to Culloden 

 Moors, six miles south of Inverness, in the Lowlands of the counties 

 of Moray and Nairn, and the neighbouring parts of Banff and 

 Inverness, great part of which is occupied by conglomerates and 

 sandstones belonging to the Old Red system. All the higher and 

 southern parts of this tract consist of primary rocks, mostly gneiss, 

 in many places traversed by numerous branching and inosculating 

 veins of granite, for the most part composed of very large crystals of" 

 red felspar and grey quartz, with a few scales of mica ; but occa- 

 sionally different parts of these veins consist of a fine-grained grey 

 granite, with a greater abundance of mica, and, like the others, 

 derived from granitic masses underneath, apparently of the same 

 age. At Park, two miles south of Nairn, at Dulsie Bridge on the 

 Findhorn, and at Coulmony (PL XI. fig. 1), between that river 

 and Lethen, porphyritic granite, like that of Aberdeen, is seen in 

 mass, and the neighbouring gneiss is much broken up, interlaced 

 with a network of granite, and considerable portions of the strata 

 are entangled in the eruptive rock. 



The gneiss usually forms lengthened ranges of low hills, having a 

 general direction of S.W. and N.E., nearly parallel to the great 

 Caledonian vaUey, with steep sides towards the S.E., and sloping off 

 gently in the opposite direction. The course of all the streams flow- 

 ing into the south side of the Moray Frith observes nearly the same 

 direction ; and up the valleys in which they flow, the several mem- 

 bers of the sandstone-series extend to very different distances, rest- 

 ing on the lower slopes and wrapping round the south-eastern ex- 

 tremities of the hills. They also occur in insulated patches, and 

 different parts of the series come into contact with the gneiss in 

 contiguous valleys or along the same stream, showing that during 

 the whole period of the deposition of the Old Red Sandstones of the 

 Moray Frith very extensive denudations were taking place. The 

 primary rocks have been exposed in different places within the sand- 

 stone districts ; and spurs and transverse ridges often project from 

 the principal ranges, cutting off the different parts of the secondary 

 rocks from each other. The general direction of the primary strata 

 is nearly E. and W., the dip being for the most part from 45° to 65° 

 S. ; but they are often vertical, and where much broken up by gra- 

 nite, as at some places on the Rivers Findhorn and Lossie, they 

 are contorted, and dip in all directions and at all angles. On the 

 other hand, the sandstones, wherever they have been observed in 

 contact with the primary rocks, rest on the edges of the latter, and 

 dip at an angle of from 8° to 12° in the opposite direction, or a httle 

 "W. of N.,— the granite-veins terminating at the junction with the 



