This is a cave in the Mountain Limestone, with a wide entrance looking to the north-east at about 70 feet above the level of the valley beneath, up which the tide has recently flowed. The cave extends tortuously for 30 or 40 yards into the axis of a ridge which is a spur of the “Ridgeway,” extending from Pembroke to Tenby, composed of the Old Red, the strike of which is east and west.

Within, the cave is distinguished by chambers, alternating with narrow passages. The floor is generally not more than three feet deep, at which depth the limestone is met with as at the roof and sides. The entrance being conspicuous, it is often visited from curiosity, but has never before been carefully explored for the definite purpose of discovering works of ancient art. This search was prompted by the recent discoveries in France and at Hoxne, strongly seconded by the fact that above, on the Ridgeway, some six or seven barrows exist, which yielded to the reporter and others a few years since, not only cinerary urns, but also well-shaped flint arrow-heads.

So much by way of introduction.

The Section will be glad to learn that the search in this cave for flint weapons has been successful, and that the number found is seventy-three, including the identical lumps of flint which remained after the chips had been struck off, when from their reduced size they were no longer capable of yielding flakes sufficiently large to answer the destined purpose, whatever that might be.

Whenever we begin to think about the formation of the universe we get at once into the realms of speculation, and the only value of our thoughts rests in their probability. In everything unknown we must first form an idea—that is, speculate; then, by partial gatherings of facts, or by positive reasoning, we may theorize. Ultimately, by the accumulation of evidence, we may prove that which, in the first place, we only imagined. When first men observed the sun, they regarded the earth as a flat plain, over which the sun passed in his heavenly course, and below which, at eve, he retired to rest. It was not until many ages had elapsed that the world came to be regarded as round, and even then it was long before the sun was considered as a fixed centre of the planetary system revolving round him.

By no nation of ancient times has astronomy been more advanced than the Greeks. Not that the Greeks ever worked out much to a proved result, but they were an imaginative people, and they invented notions. If one theory or speculation was disproved, they invented another; and, hit or miss, they always seemed to have fresh ideas in reserve. In some things astronomical, as in many other things that the world believes in, we may be heretics, and we admit we do not adhere to all the cosmical, physical, geological, and spiritual tenets of the popular faiths. We may not entirely believe in the perfect stability of the universe; we may doubt the eternal endurance of the sun's bright rays; and we may not quite acquiesce in the unchangeable permanence of tne planetary orbits: in short, we do not believe in the permanence of anything whatever in creation. All ever has been change, and changeful all things ever will be. Diversity and change are visible in the first created things of which any relics have been left us.

The wonderful remains of the Archæopteryx, recently acquired for the British Museum, have naturally drawn attention to a muchneglected department of palæontology; and it will therefore not only be interesting, but useful also to the advance of science, to pass under review, at the present time, the state of our knowledge of the former existence of birds during past geological ages. The early authors, for the most part, speak not of fossil bird-remains properly so called, but in reality of mere incrustations by “petrifying springs,” of the fanciful tracery of dendritic markings, or the imagined resemblances of oddly-formed stones. Thus Albertus Magnus, in his book ‘De Mineralibus,’ printed in 1495, describes a fossil nest, with eggs, on the branch of a tree. This might or might not be a true fossil, but our recent discoveries of fossil birds and reptiles' eggs, and the knowledge we have now of delicate objects truly fossilized, such as insects, fruits, flowers, and feathers, renders it possible that some of the old records of such may have had a foundation of truth, and gives a probability that some at least may be brought within the capacity of belief as actual facts.

With this view, we shall quote from the old authors all the passages known to us, commenting on them as occasion may require; and in thus working up the bibliography of fossil ornithology and arranging the whole of our knowledge of the subject, as far as we have the power to do so, we shall be able to separate facts from fictions, and give a solid basis for further investigations in the future study of ornithological palæontology.

The existence of layers of limestone at various intervals among the rocks, while in the intermediate strata there is a remarkable deficiency of that substance, is a fact which I have not seen hitherto satisfactorily accounted for, but of which we may hope to find some rational explanation.

In the British Museum there are several specimens of “papilionaceous” flattened bodies exhibiting six or more concentric lines radiating from two nuclei on either side of an elevated medial line. The stone in which they are embedded is unquestionably the Stonesfield slate; it contains the characteristic Trigonia angulata, Rhynchonella, Ostrea, and Modiola Sowerbyana, D'Orb. (= plicata, Sowerby). The enigmatical bodies to which I now allude are stained of a deep redferruginous colour, the matrix retaining the grey tint and crystalline texture of the Stonesfield slate. On comparison between these remains and those of the specimens of Geomyda spinosa, from Singapore, in the British Museum, presented by Sir A. Smith, a comparison which was suggested to me by Mr. Davies, whose accurate discrimination first threw light upon the nature of the present evidence, I have been led to consider that the specimens in the Fossil Gallery represent the second, third, and fourth median scutes of a tortoise allied to the recent African species. The fossils and their corresponding impressions from the Stonesfield slate afford, according to my interpretation, evidence of the texture of the horny scutes which were developed outside the bony carapace of the old Oolitic tortoise. A particular interest is attached to these specimens, as they were considered by the late Edward Forbes as Trigonellites, or opercula of Ammonites.