occurs at isolated spots in a tract of 500 miles. The English E. elliptica is about 400 miles away from its Hanoverian type. These species were probably represented at their several epochs by isolated communities in distinct lakes, lagoons, and deltas; just as some of the recent species are recognized at different localities, occasionally far apart: thus E. gigas has been found in pools at Strasbourg, at Toulouse, and in Tunis (the first and last upwards of 800 miles apart); E. Dahalacensis is known to live in both Abyssinia and Mesopotamia (1600 miles apart); and E. Melitensis at Malta and in Sicily (at least 50 miles apart). There are, however, very many more species recorded as existing at the present period (22) than we have found fossil in the deposits of any one past period, only two at most being the number of known species for any one of the recognized great formations. This, however, is partly due to zoological distinctions founded on the limbs and other parts of the body in some of the existing species, but not recognizable in the fossil state; partly, perhaps, to imperfect search in the strata; and possibly, in some degree, to a greater differentiation of the more modern forms, if their specific distinctness is accurately determined *.

Further search for, and strict examination of, fossil and recent specimens, with careful records of the exact conditions of the strata imbedding the former, and of the habitats of the latter, are necessary before we can be satisfied on many of the points, referred to above, in the geological history of Estheria and its Phyllopodous allies.

3. On the FLORA of the DEVONIAN PERIOD in NORTH-EASTERN AMERICA. Appendix. By J. W. DAWSON, LL.D., F.R.S., F.G.S. [Published in the February Number of the Journal, by permission of the Council. See vol. xviii. p. 329.]

JANUARY 7, 1863.

SPECIAL GENERAL MEETING.

It was Resolved:

I. That the number of Foreign Members be in future limited to Forty, instead of Fifty as heretofore.

II. That a Class of Foreign Correspondents be instituted, not exceeding Forty in number.

III. That the Foreign Members shall be elected out of the list of Foreign Correspondents.

It was also Resolved that the Meetings of the Society shall be held in the Society's Rooms at Somerset House, on and after the Anniversary Meeting next ensuing.

*Some of the recent species are known only by their carapaces; and, if fossilized, would be with difficulty discriminated one from the other. The determination by the valve-characters alone is as likely to lead to an over-estimate of the number of recent species, as to a too cautious consideration of the fossil species.

ORDINARY GENERAL MEETING.

John Daglish, Esq., Hetton, Durham; Griffith Davies, Esq., 17 Cloudesley Street, Islington; John Walter Lea, Esq., B.A., The Grange, Shepperton Green, Chertsey; and Henry Michael Jenkins, Esq., Assistant-Secretary of the Geological Society, 22 St. George's Road, London, were elected Fellows.

The following communications were read :

1. On the LOWER CARBONIFEROUS BRACHIOPODA of NOVA SCOTIA. By THOMAS DAVIDSON, Esq., F.R.S., F.G.S., &c.

[PLATE IX.]

Ar the request of Dr. J. W. Dawson, F.R.S., F.G.S., Principal of McGill University, Montreal, I have examined the Brachiopoda collected by him from the Lower Carboniferous formation of Nova Scotia, as well as those obtained by Sir C. Lyell during his first journey in America, and I now submit the result of this examination to the Geological Society.

The geology of Nova Scotia has already received the attention of several distinguished observers; and I may mention that, although prior to Sir C. Lyell's visit to the country in question Mr. R. Brown had described the limestone of East River and Cumberland as Lower Carboniferous, the limestones of Windsor and Shubenacadie were at that time regarded as "New Red Sandstone" or "Permian." Sir C. Lyell was the first to maintain that the whole was of Carboniferous age; and, by so doing, he unravelled a complication which might for a time have involved the geology of the country in much confusion. He may therefore justly claim to have been the first geologist who was able to determine the geological age of the Gypsiferous strata of Nova Scotia, which he considered to be a member of the Carboniferous group instead of the Triassic or the Permian, or both of them, as previously conjectured *. Dr. Dawson informs me that his first papers on the subject were the results of investigations which he made to test Sir C. Lyell's views, and that Mr. Brown and he followed up these observations, and accumulated a vast number of facts subsequently published in his Acadian Geology,' and from which I extract the following synopsis of the Carboniferous rocks of Nova Scotia†, in order to point out the horizons at which the Brachiopoda have been obtained.

Upper or Newer Coal-formation.

Greyish and reddish sandstones and shales, with beds of conglomerate, and a few thin beds of limestone and coal; the latter not of economic importance. Thickness, 3000 feet or more.

Fossils:-Coniferous wood, Calamites, Ferns, &c.

* See Sir C. Lyell's Travels in North America, with Geological Observations on the United States, Canada, and Nova Scotia,' vol. ii. p. 204, 1845. +"An Account of the Geological Structure and Mineral Resources of Novs Scotia," &c. 1855.

Localities:-Cumberland, north of the Cobequid Mountains; Northern Colchester, Pictou; well exposed on the Joggins coast, and on the coast of Northumberland Straits, west of Pictou Harbour.

Lower or Older Coal-formation.

Grey and dark-coloured sandstones and shales, with a few reddish and brown beds; valuable beds of coal and ironstone; beds of bituminous limestone, and numerous under-clays with Stigmaria. Thickness, 4000 feet or more.

Fossils:-Stigmaria, Sigillaria, Lepidodendron, Poacites, Calamites, Ferns, &c., erect Trees in situ, remains of Ganoid Fishes, Cypris, Modiola, and three species of Reptiles.

Localities:-Cumberland, north of Cobequid Mountains, Pictou, especially East River, Port Hood, Inhabitants' Basin, and other places in Inverness and Richmond; eastern part of Cape Breton; parts of Colchester, south of Cobequid Mountains. The finest exposures are in the South Joggins, and near Sidney, Cape Breton.

Lower Carboniferous or Gypsiferous Formation.

Great thickness of reddish and grey sandstones and shales, especially in the upper part; conglomerates, especially in the lower part; thick beds of limestone (with marine shells) and of gypsum. Thickness, 6000 feet or more.

Fossils:-Productus, Terebratula, Encrinites, Madrepores, and other marine remains in the limestone. Coniferous wood, Lepidodendron, Poacites, &c., in the shales and sandstone. Scales of Ganoid Fishes very abundant in the shales associated with the lowest beds, in which are also coaly seams and bituminous beds.

Localities:-Northern Cumberland, Pictou, Colchester, and Hants; Musquodoboit, in Halifax county; Guysboro (in part), parts of Inverness, Richmond, Cape Breton, and Victoria.

All the Brachiopoda, with one exception, are stated to have been derived from the Lower Carboniferous or Gypsiferous formation; and, although the fossiliferous rocks submitted to my examination vary considerably in composition and texture, it is evident that the larger number of the species continued to live together for a considerable period of time. There is a compact, light-yellowish-grey limestone, full of Spirifera glabra, Terebratula sacculus, Productus Cora, &c.; while some limestones, with the same fossils, are almost black in colour; others are arenaceous, yellow, and full of small cavities, the interior of the shells being often hollow; and, again, other limestones, as that of Brookfield, are formed almost entirely of shells, Bryozoa, &c., so closely packed that there appears in some cases to be hardly any cementing material or intervening matrix. Some shales also contain flattened valves of Streptorhynchus crenistria. Dr. Dawson believes that this remarkable lithological difference in the Lower Carboniferous rocks of Nova Scotia may have been caused through the limestones having been deposited in limited basins or narrow straits, and probably at a time of much volcanic disturbance;

1

hence the great local diversity. He is, moreover, inclined to consider that in each locality the "Lower Limestones" are darker in colour, more laminated, and less fossiliferous than the upper; also that the individual beds become darker, more impure, and less fossiliferous as they approach the high lands which formed the old shorelines; but that there are, of course, exceptions to these statements. The very remarkable shell-rock above described occurs at Brookfield, a little east of the Shubenacadie River; it was first discovered by the late Mr. G. Dunkin, and by him made known to Dr. Dawson. It is in the line of strike of the Shubenacadie beds, and is doubtless a continuation of them. This rock has such a great general resemblance to certain Permian shelly limestones, with which I am acquainted, that, had the specimens been submitted to me without any indication as to their geological age, I should certainly have felt somewhat puzzled to determine whether I had to deal with a Permian or a Carboniferous rock and its fossils; and, indeed, when M. de Verneuil determined these fossils for Sir C. Lyell in 1845, he enumerated, among others, Terebratula elongata and T. sufflata, Schl., Spirifera cristata, Schl., Avicula antiqua, Münster, a Modiola, a Littorina, and one or two other fossils which he considered to be common to both the Permian and the Carboniferous strata. Although I may modify to some extent the lists of species published by Sir C. Lyell and Dr. Dawson, I quite coincide with what is stated by the former author, at p. 205 of his Travels,' viz., "That geologists should at first arrive at this result (of considering the rocks in question as the equivalents in age of the Permian of Russia) will surprise no one who is aware how many of the fossils of our Magnesian Limestone and Coal resemble each other, or who studies the lists given at p. 218, in which several species both of shells and corals from Nova Scotia, identical or closely allied to well-known Permian or Magnesian Limestone forms, are enumerated."

This is important to note: for it was written in 1845, just at the time the celebrated authors of the great work on Russia in Europe and the Ural Mountains (published in 1845) arrived from that country; and it denotes how strongly impressed they were that a certain number of Carboniferous species had continued to exist during the Permian period. Subsequent researches have confirmed this view, and considerably multiplied the number of species common to the two epochs; and it has been proved in the most satisfactory manner that the Permian formation is the natural continuation of the great Carboniferous system, of which it composes the upper portion, although it is desirable to distinguish the group by the separate designation of "Permian." It is not the Mollusca and Plants of the Permian period alone which, as M. Marcou supposes, have a Paleozoic aspect, but, as M. de Verneuil*, Mr. Kirkby †, and others have already shown, the whole bulk of the animal and vegetable remains found in the Permian rocks bear the most unmistakeable Paleozoic stamp. But, again, it would be fallacious to * Bulletin de la Soc. Géol. de France, 2e sér. vol. xix. pp. 599, 627 (1862). † Annals and Mag. Nat. Hist. 3rd Series, vol. x. Sept. 1862.

suppose, as many have done, that at the expiration of each of the supposed great divisions of the sedimentary crust of the earth, namely, the Paleozoic, Mesozoic, and Cainozoic, there was a complete extinction and renewal of life. Such an idea in 1863 would be completely out of place; for it has been shown over and over again that many Paleozoic genera have not only continued to be represented during a greater or less portion of the Mesozoic time, but also throughout the entire geological sequence of sedimentary strata. It is also quite evident that the admirable science of paleontology, notwithstanding its rapid strides and great discoveries, is far from having revealed all its secrets, and is still in its youth. It cannot, therefore, be expected that those who are now endeavouring to decipher its difficult language can yet be in a position to furnish the key to the genealogy of the numerous forms they daily meet with in almost every rock and latitude, or that they can link together the multitudinous and varied forms composing any class, and far less the whole animal kingdom.

It is quite true that, in the present state of our knowledge, there appears to exist between the Paleozoic and Mesozoic divisions or periods a much wider break or difference in the life-groups than between the individual systems of which these divisions are composed. It is, however, highly probable that, when our science is more advanced, a closer agreement will be obtained. Experience has taught us that no genus or species, once become extinct, is ever recreated; and it is to my mind quite certain that, as long as the same genus is represented in any successive geological formations, this alone is a positive proof that life was not interrupted during that period. We are all aware that a certain number of genera of different classes passed from the Paleozoic into the Mesozoic period; but I will not at present enter into the discussion of this subject further than to mention that, among the BRACHIOPODA, Terebratula, Spirifera, Spiriferina, Cyrtia, Athyris, Rhynchonella, Leptana, Crania, Discina, and Lingula passed from the Paleozoic into the Mesozoic division. The Triassic species have not yet been sufficiently compared with those from our Paleozoic deposits; but a glance at some of the St. Cassian forms, or even at Klipstein's and Münster's figures, will suffice to remove the idea that there was a complete extinction of life at the close of the Paleozoic period and an entire renewal of species at the commencement of the Mesozoic epoch.

Geologists and paleontologists are fully aware that the Permian fauna is not nearly so rich in species as that of the Carboniferous period. When we, therefore, compute the percentage of species common to the two, the Permian fauna must be taken as the standard, not the Carboniferous. The subject of the recurrence of Carboniferous species in the Permian period is far from having been completely worked out; but, since 1845, it has attracted the attention of several competent observers, amongst whom I may mention Messrs. de Verneuil, Brongniart, Geppert, Gutbier, Geinitz, Kirkby, King, Howse, Rupert Jones, and myself, in Europe; Messrs. Meek and Hayden, Swallow and Hawn, Dr. Shumard and Mr. Newbury, in America.

VOL. XIX. PART I.

M