1858.] MURCHISON SANDSTONES OF ELGIN. 425 



Though not on the same line of section, the conglomeratic beds of 

 Scat Craig, which lie a little to the east, are to be referred to this 

 member of the series, i.e. to strata of a rather younger age than the 

 lowest fish-beds of Lethen Bar, Clune, &c., or the Caithness strata. 

 At Scat Craig the conglomerate is chiefly of greenish colours, though 

 red in parts, and is bound together with a calcareous cement and a 

 sandy matrix of green, red, grey, and yellow colours, such masses 

 being arranged in flattened concretionary forms. 



There are, in fact, passages from fine grey grit to pebbly con- 

 glomerates, both angular and round, with which white calc-spar is 

 disseminated. The whole of this mass, like the strata upon the 

 Findhom, dip at very low angles only to the N. and N.N.W. 



The interest which specially attaches to the fossil fishes found at 

 Scat Craig is, that, whilst the Pterichthys major and other species of 

 that genus, as well as the Aster olepis, are common to Caithness 

 and the west of Moray (Lethen Bar, Clune, Altyre, &c.), there are 

 other forms, such as the Dendrodus latus and D. strigatus, Lamnodus, 

 and Cricodus, which, as well as the Asterolepis Asmusii, are common 

 in the Old Red of Russia, where I have myself detected them. The 

 Scat Craig beds oifer, besides, zoological evidence of an ascending 

 order from the Caithness group into the superior or Holoptychius- 

 band so common in Perthshire and Fifeshire ; for associated with the 

 true Caithness fishes above mentioned we meet (for the first time in 

 ascending order) with the Holoptychius Nohilissimus, Ag., of Perth- 

 shire and the south of Scotland. 



There is a union, therefore, in this one mass of conglomerate, of 

 genera which in other places mark the central and upper members of 

 the series. Moreover, it is not to be forgotten that in the overlying 

 beds near Scat Craig the red conglomerate and sandstones first become 

 foxy yellow, and then pass into the ordinary yellow and light-co- 

 loured sandstone in which the Holoptychius is, as far as I know, 

 the chief fossil, the other and older forms having disappeared. 



We shall afterwards see how the lower and central sandstones and 

 conglomerates, expanding largely in their range to the east, again 

 exhibit the Caithness group of ichthyolites at Tynet, Dipple, and 

 Gamrie. 



In the meantime let us continue the transverse ascending section 

 of the Lossie. Advancing from the yellowish grit and sandstone 

 with remains of fishes, after a considerable amount of denudation 

 and consequent obscuration by gravel, a coarse red conglomerate con- 

 taining blocks of some size is seen to occupy strong beds, and to be 

 of great thickness, on the right bank of the stream, above the Manse 

 of Birnie, — all the strata being inclined to the N". or N. by W. 



Judging, however, from the generally uniform and consistent dip 

 of all these beds, I satisfied myself that one of the mottled red and 

 greenish-grey concretionary masses, pointed out to me by Mr. Gordon, 

 must be considered to lie beneath the Bii-nie conglomerate, and range 

 along a tract which in the bed of the Lossie has been denuded. 



In fact, the tendency to form a cornstone, or concretionary cal- 

 careous rock, has been already adverted to, as showing itself in the 



