398 PROFESSOR GEIKIE ON THE 
glomerates, so conspicuous to the west and north, have thinned off and nearly 
disappeared on the southern side of the Moray Firth, the true order of succes- 
sion is much concealed by superficial detritus, and the three groups of the 
system are there very ill defined. They do not therefore attempt to enter into 
any details regarding the Old Red Sandstone of that region, contenting them- 
selves with a notice of the cornstone so copiously developed there, and of the 
strata with which it is associated. | 
- In the year 1836, Mr Martin of Elgin, who had a year previously obtained 
a prize from the Highland and Agricultural Society for an “Essay on the 
Geology of Morayshire,” * discovered fossils in the conglomerate of Scat Craig 
near Elgin. These were eventually recognised as similar to forms which had 
already been obtained from undoubted Old Red Sandstone elsewhere, so that 
the reference of the Morayshire conglomerates and sandstones to that forma- 
tion was confirmed by paleontological evidence. Two years afterwards, viz., 
in the autumn of 1838, Dr JouN MALcoLMson began an extensive and laborious 
investigation of the region, specially with the object of unravelling the history 
of its Old Red Sandstone, and of ascertaining whether or not it could not be 
proved to be much more fossiliferous than the solitary locality near Elgin 
seemed to denote. He carried on his observations along the whole of the 
northern sea-board, from the cliffs of Aberdeenshire to the shores of the 
Cromarty Firth, discovering in many localities remains of fossil fishes, some of 
which he could identify with forms found at Cromarty, in Caithness, and in 
Orkney, while others appeared to be new. Ina paper read before the Geolo- 
gical Society (June 1839), he announced the important conclusions to which he 
had been led, and which may be briefly summarised as follows :—The Old Red 
Sandstone system of the north of Scotland may be arranged in three divisions. 
Of these, the lowest member (I.), consists of three formations—(a) The great 
conglomerate ; (b) Red sandstones, shales with calcareous nodules and lime- 
stones abounding in remains of fishes and plants; (c) Argillo-caleareous red 
sandstones and conglomerates. The central member, or cornstone, group (II.), 
is composed of sandstones, calciferous conglomerates, marls, and cornstones, 
and abounds in remains of fishes all different from those of the middle zone of 
the lower beds. The highest member (III.) consists of fine white, grey, and yellow 
siliceous sandstones, conglomerates, and cornstones. He places the middle 
zone of the lowest division on the same parallel with the flagstones of Orkney 
and Caithness, and the tile-stones of England; while he brackets together, as 
equivalent strata, his central division with the sandstones of Clashbennie in 
Perthshire (Holoptychius Nobilissimus beds), and the Herefordshire cornstones. 
It is impossible to traverse the scattered sections of Moray and Nairn without 
* “Trans, Highland Soc.” new series, vol. v. p. 417. 

