seas of Venus, or even of Jupiter, which, from its enormous bulk, though greatly more distant from the sun than our earth, may still powerfully retain the internal heat. I still pursued my inquiries, and received a valuable auxiliary in a gentleman from India, Dr. John Malcolmson, of Madras--a member of the London Geological Society, and a man of high scientific attainments and great general knowledge. Above all, I found him to possess, in a remarkable degree, that spirit of research, almost amounting to a passion, which invariably marks the superior man. He had spent month after month under the burning sun of India, amid fever marshes and tiger jungles, acquainting himself with the unexplored geological field which, only a few years ago, that vast continent presented, and in collecting fossils hitherto unnamed and undescribed. He had pursued his inquiries, too, along the coasts of the Red Sea, and far upwards on the banks of the Nile; and now, in returning for a time to his own country, he had brought with him the determination of knowing it thoroughly as a man of science and a geologist. I had the pleasure of first introducing him to the ichthyolites of the Lower Old Red Sandstone, by bringing him to my first-discovered bed, and laying open, by a blow of the hammer, a beautiful _Osteolepis_. He was much interested in the fossils of my little collection, and at once decided that the formation which contained them could be no representative of the Coal Measures. After ranging over the various beds on both sides the rectilinear ridge, and acquainting himself thoroughly with their organisms, he set out to explore the Lower Old Red Sandstones of Moray and Banff, hitherto deemed peculiarly barren, but whose character too much resembled that of the rocks which he had now ascertained to be so abundant in fossils, not to be held worthy of further examination. He explored the banks of the Spey, and found the ichthyolite beds extensively developed at Dipple, in the middle of an Old Red Sandstone district. He pursued his researches, and traced the formation in ravines and the beds of rivers, from the village of Buckie to near the field of Culloden; he found it exposed in the banks of the Nairn, in the ravines above Cawdor Castle, on the eastern side of the hill of Rait, at Clune, Lethen-bar, and in the vale of Rothes--and in every instance low in the Old Reel Sandstone. The formation hitherto deemed so barren in remains proved one of the richest of them all, if not in tribes and families, at least in individual fossils; and the reader may form some idea of the extent in which it has already been proved fossiliferous, when he remembers that the tract includes as its extremes Orkney, Gamrie, and the north-eastern gorge of the great Caledonian Valley. The ichthyolites were discovered in the latter locality in the quarry of Inches, three miles beyond Inverness, by Mr. George Anderson, the gentleman to