of Oolitic, and not of Carboniferous age. No account of their researches, however, appears to have been printed.
In 1826 Mr. (afterwards Sir Roderick) Murchison visited the county, and made that careful survey of the Jurassic strata in Sutherland, Ross, and Cromarty, to which reference has already been made (Trans. Geol. Soc. 2nd ser. vol. ii. pt. 2, p. 293).
In the following year (1827) Murchison returned to the Highlands in company with Professor Sedgwick. On this occasion, the Secondary rocks were reexamined, and the first detailed study made of the Triassic rocks of Elginshire (Trans. Geol. Soc. 2nd ser. vol. ii. pt. 3, p. 353, and vol. iii. pt. 1, p. 125).
At this period Dr. Knight, of Aberdeen, had already detected the fact of the existence of chalk-flints over a large area in the county of Aberdeen ; and in a paper published in the Edinburgh Philosophical Magazine in 1831, Mr. Christie called attention to the occurrence of chalk-flints at Boyndie Bay, Banffshire.
In 1832 appeared the first edition of the admirable ' Guide to the Highlands ' by George and Peter Anderson, of Inverness, in which some valuable geological observations are recorded.
The same year Dr. Gordon, in a letter to Sir Roderick Murchison, read before the Geological Society, gave the first notice of the existence of a patch of Secondary rock in Morayshire at Linksfield, or Cutley Hill, near Elgin (Proc. Geol. Soc. vol. i. p. 391).
In the year 1835 the Highland and Agricultural Society published a prize essay on the ' Geology of Morayshire,' the work of Mr. John Martin. This work contains many valuable details connected with our subject. In 1838 Dr. Malcolmson showed that the beds at Linksfield presented remarkable resemblances in mineral characters to the English Wealden and Purbeck, to which period he suggested that they belonged. In the same year appeared his admirable essay on the Old Red Sandstone of Morayshire, in which he treated of the beds now placed both on palaeontological and stratigraphical grounds in the Trias.
Mr. R. Hay Cunningham's ' Geognosy of Sutherlandshire,' another of the prize essays of the Highland and Agricultural Society, appeared in 1839. In this work, however, which contains such an admirable account of the Palaeozoic rocks of the county, scarcely any fresh facts are added with regard to the Secondary rocks.
In 1842 appeared Mr. Duff's ' Sketch of the Geology of Moray,' in which many valuable details are given concerning the rocks of that county (which are now placed in the Trias), and also with regard to the fragments of Jurassic rocks scattered over the county, which are now proved to be transported masses included in the Boulder- clay.
Mr. Alexander Robertson, of Inverugie, laid before this Society, in the years 1843 and 1846, admirable essays on the section below the coal of Brora, showing that there were intercalated in the series bands of freshwater shells, and insisting that, from the resemblance of these strata to the Wealden, they ought to be classed with that formation (Proc. Geol. Soc. vol. iv. p. 173, and Quart. Journ. Geol.
