The principal difference here observable is in the somewhat greater size of A. concavus, and the larger umbilic of A. M'Clintocki. It certainly resembles this well-known ammonite very closely; and it appears to me difficult to imagine the possibility of such a fossil living in a frozen, or even a temperate sea.

The discovery of such fossils in situ, in 76° north latitude, is calculated to throw considerable doubt upon the theories of climate which would account for all past changes of temperature by changes in the relative position of land and water on the earth's surface. No attempt, that I am aware of, has ever been made to calculate the number of degrees of change possible in consequence of changes of position of land and water; and from some incomplete calculations I have myself made on the subject, I think it highly improbable that such causes could have ever produced a temperature in the sea at 76° north latitude which would allow of the existence of ammonites, especially ammonites so like those that lived at the same time in the tropical warm seas of the south of England and France, at the close of the Liassic, and commencement of the lower Oolitic period.

During the course of the same Arctic expedition in which these organic remains were found, Captain Sir Edward Belcher discovered in some loose rubble, of which a cairn was built on Exmouth Island (lat. 77° 12' N., long. 96° W.), vertebral bones of, apparently, same liassic enaliosaurian. All doubt as to the reality of this discovery, and all idea of accounting for the occurrence of such remains by drift, must be abandoned, as the fossils found by M'Clintock were unquestionably in situ, and it is impossible to evade the consequences that follow to geological theory from their discovery.

Captain Sherard Osborn, also, found broken vertebræ of an ichthyosaurus, 150 feet up Rendezvous Hill, the north-west extreme of Bathurst Island: of these specimens, one lay among a mass of stone that had slipped from the N.W. face of the hill; the other was by the side of a ravine or deep watercourse on the southern face of the same elevation. I have no doubt but that they were in situ.

I am well aware that the question of light in the Arctic seas will be disposed of by some geologists, who will remind us that the saurians, and probably the ammonites, were endowed with a complicated optical apparatus, rendering them capable of using their eyes, not only for the distinct vision of objects differing greatly in distance, but also of using them, under widely differing conditions of light and darkness; and I readily admit the force of such observations.

But what are we to say as to the question of temperature? It was certainly necessary for an ammonite to have a sea free from ice, on which to float and bask in the pale rays of the Arctic sun; and therefore I claim a temperature for those seas, at least similar to that which now prevails in the British Islands: and I may add that the ammonite, from its habits, was essentially dependent on the temperature of the air, as well as on that of the water.

There is at present a difference of 49·5° F. between the mean annual temperature of Point Wilkie and Dublin; and if this change of temperature be supposed to be caused by a change of the relative positions of land and water, the temperature of Dublin, or of some place on the same parallel of latitude, must be supposed to be raised to 99·5° F.; while the temperature of the thermal equator will exceed 124°—a temperature only a few degrees below that requisite to boil an egg! I reject, without scruple, a theory that requires such a result, which must be considered as a minimum; as it is probable that the ammonite required a finer climate than that of Britain for the full enjoyment of his existence.

The theory of central heat, also, appears to me to be open to the same objection, as a mode of explaining this remarkable geological fact; for it will simply add a constant to our present climates, leaving the differences to remain, as at present, to be accounted for by latitude and distribution of land and water. The astronomical theory of Herschel, also, which would account for former changes of climate by changes in the radiating power of the sun, would only increase the temperature at each latitude, leaving the differences as at present.

The only speculation with which I am acquainted, which is capable of solving this opprobrium geologicorum, is the hypothesis of a change in the axis of rotation of the earth, the admission of which, as a geological possibility, is mathematically demonstrable, and which has recently had some singular evidence in its favor advanced by geologists. In 1851, I brought forward, at the Geological Society of Dublin, a case of angular fragments of granite occurring in the carboniferous limestone of the County Dublin; and explained the phenomena by the supposition of the transporting power of ice. In 1855, Professor Ramsay laid before the Geological Society of London a full and detailed theory of glaciers and ice as agents concerned in the formation of a remarkable breccia, of Permian age, occurring in the central counties of England; and still more recently the same agent has been employed by the geological surveyors of India to account for the transport of materials at geological periods long antecedent to those in which ice transport is commonly supposed to have commenced. The motion of the earth's axis would reconcile all the facts known, and it must be regarded as a geological desideratum to determine its amount and direction, and to assign the cause of such a movement. The solution of this problem I regard as quite possible.

It is well worthy of remark, that the arguments from the occurrence of coal-plants and ammonites strengthen each other; the coal-plants rendering the question of light, and the ammonites that of heat, insuperable objections to the admission of any received geological hypothesis to account for the finding of such remains, in situ, in latitudes so high as those of Melville Island, Prince Patrick's Island, and Exmouth Island.

V.—The Superficial Deposits.

The surface of the ground, where exposed, throughout the Arctic Archipelago, does not appear to be covered with thick deposits of clay or gravel, such as are found generally in the north of Europe, and referred by geologists to what they call "the Glacial Epoch." There are not, however, wanting abundant evidences of the transport of drift materials, and there is some good evidence, collected by Captain M'Clintock, of the direction in which the drift was moved.

Specimens of granite, which I have no hesitation in referring to the characteristic granite of the west side of North Somerset, were found at Leopold Harbor (North Somerset) and at Graham Moore Bay (Bathurst Island); one of these localities is N.E. and the other N.W. of the granite of North Somerset, from which I infer that there was no constant prevailing direction for the drift ice that carried these boulders, but that they were transported to the northward in various directions, according to the varying motion of the currents that moved the ice. The boulder of granite at Port Leopold is 100 miles N.E. of the granite which gave origin to it; and the specimens from Graham Moore Bay are 190 miles to the N.W. of their source.

At Cape Rennell (North Somerset), in a direction intermediate between the two former directions, a remarkable boulder of the same granite was found, confirming the general direction of the transporting force from south to north. Its position and size are thus recorded by Captain M'Clintock:—"Near Cape Rennell we passed a very remarkable rounded boulder of gneiss or granite; it was 6 yards in circumference, and stood near the beach, and some 15 or 20 yards above it; one or two masses of rounded gneiss, although very much smaller, had arrested our attention at Port Leopold."

It is well known that Captain Sir Robert M'Clure brought home specimens of pine-trees found in the greatest abundance in the ravines on the west coast of Baring Island; one of his specimens preserved in the museum of the Royal Dublin Society measures 15 inches by 12 inches, and contains three knots that prove it formed a portion of the stem high above its root. The bark is not found on this specimen, which does not represent the full thickness of the tree; I have estimated that this fragment contains 70 rings of annual growth.

Similar remains were found by Captain M'Clintock and Lieutenant Mecham in Prince Patrick's Island, and in Wellington Channel by Sir Edward Belcher. On the coast of New Siberia, Lieutenant Anjou found a clay cliff containing stems of trees still capable of being used as fuel. The original observers all agree in thinking that these trees grew where they are now found; and Captain Osborne, in mentioning Sir Roderick I. Murchison's opinion that they are drift timber, justly adds the remark, that a sea sufficiently free from ice to allow of their being drifted from the south would indicate also a climate sufficiently mild to allow of their having grown upon the land where they now occur. Mr. Hopkins, in his anniversary address as President of the Geological Society of London, has published a remarkable geological speculation, which would account for the facts above mentioned.[36] So far as the evidence of drift boulders is concerned, I have shown that the direction of the currents was from the south; a fact which falls in with the drift theory, so far as it goes.

We cannot, however, dissociate these trees from the facts connected with the distribution of the remains of the Siberian Mammoth in Asia and America. It is now known that this elephant was provided with a warm fur, and that his food was of a kind which grows even now in Northern Siberia; so that the drift theory, which was formerly supposed necessary to account for the occurrence of these remains, has now been quietly dropped, sub silentio, by the geologists. Many other drift theories have, in like manner, lived their short day, and gone the way of all false hypotheses; among others, the drift theory of the origin of coal. Further investigation may show that the glacial epoch of Europe was one of a very different character in Asia and America, and that, while glaciers clothed the sides of Snowdon and Lugnaquillia, pine forests flourished in the Parry Islands, and the Siberian elephants wandered on the shores of a sea washed by the waves of an ocean that carried no drifting ice.

There is abundant evidence, however, that the Arctic Archipelago was submerged in very recent geological periods; for we know that subfossil shells, of species that now inhabit the waters of the neighboring seas, are found at considerable heights throughout the whole group of islands. M'Clure found shells of the Cyprina Islandica, at the summit of the Coxcomb range, in Baring Island, at an elevation of 500 feet above the sea-level; Captain Parry, also, has recorded the occurrence of Venus (probably Cyprina Islandica) on Byam Martin's Island; and in the recent voyage of the 'Fox,' Dr. Walker, the Surgeon of the expedition, found the following subfossil shells at Port Kennedy, at elevations of from 100 to 500 feet:—

1. Saxicava rugosa.
2. Tellina proxima.
3. Astarte Arctica (Borealis.)
4. Mya Uddevallensis.
5. Mya truncata.
6. Cardium sp.
7. Buccinum undatum.
8. Acmea testudinalis.
9. Balanus Uddevallensis.

At the same place a portion of the palate-bone of a whale (Right Whale) was found at an elevation of 150 feet.

All these facts indicate the former submergence of the Arctic Archipelago, but this submergence must have been anterior to the period when pine forests clothed the low sandy shores of the slowly emerging islands, the remains of which forests now occupy a position at least 100 feet above high-water mark.

The geological map which I am enabled to publish from the data collected by Captains M'Clintock, M'Clure, Osborn, &c., is an enlargement of that which was published in 1857 by the Royal Society of Dublin, to illustrate the fine collection of Arctic fossils and minerals deposited in the museum of that body by Captains M'Clintock and M'Clure. In perfecting it for its present purpose I have availed myself of all the other sources of information within my reach, among which I am bound to mention in particular the excellent Appendix to Dr. Sutherland's 'Voyage of the Lady Franklin and Sophia,' written by Mr. Salter, Palæontologist of the Geological Survey of Great Britain.

Many of the mineral specimens from Greenland, and the fossils from Cape Riley, Cape Farrand, Point Fury and Brentford Bay, were collected by Dr. David Walker, surgeon and naturalist to the 'Fox' Expedition.

No. V.

LIST OF SUBSCRIBERS TO THE 'FOX' EXPEDITION.