and account for the great abundance of it in some such localities where we found it.

Native Iron and Cosmic Dust.

While examining the deposits during the cruise I frequently observed among the magnetic particles from our deep-sea clays small round black coloured particles which were attracted by the magnet, and I found it difficult to account for the origin of these.

On our return home I entered into a more careful examination of the magnetic particles. By means of a magnet carefully covered with paper I extracted these particles from the deposits, from the pumice-stones, and from the manganese nodules of many regions. The great majority of these magnetic particles are magnetic iron ore and titaniferous iron, either in the form of crystals, or as fine dust. In the clays, and in the manganese nodules from stations far from land and in deep water, there were again noticed many small, round spheres among the magnetic particles.

On mentioning this to Professor Geikie, he suggested that I should try the method employed by Professor Andrews of Belfast for detecting minute particles of native iron.

This process consists in moistening the magnetic particles, which have been extracted by means of the magnet, with an acid solution of sulphate of copper, when copper is at once deposited on any native particles which may be present. In this way I have detected native iron in many of our deposits, in the powdered portions of manganese nodules, and in pumice-stones.

Professor Andrews tells me that there can be little doubt that the particles on which copper is deposited are native iron, as he has found that it is not deposited on nickel, and the chances of cobalt being present are very slight. Professor Andrews warned me on the extreme precautions necessary in conducting these observations, that no iron from a hammer or other instrument should get at the specimen under observation.

It is true that all specimens of our deposits have been obtained by means of dredges and iron gear, and some of these particles may be from this source.

Many of the particles must have another origin. I have taken two of our manganese nodules, and washing them carefully, taking

1

care to let no iron instrument come near them, have broken them by rapping them together. Then taking only the interior parts of these nodules I have pulverized them in a porcelain mortar. The magnetic particles were afterwards extracted by a magnet covered with paper. Now, placing these particles on a glass slide under the microscope, and adding the sulphate of copper solution, there was in a few moments a deposit of copper on several small perfect spherules, varying in size from the 1000 to the of an inch in diameter. I have placed some of these spherules under the microscope and now show them to the Society. It will be noticed that on one the copper is not deposited all over the sphere, but in ramified spider-like lines. On the cut surface of a meteorite, from Professor Sir Wyville Thomson's collection, which I also exhibit, the copper is precipitated in precisely the same manner as on the little sphere from the manganese nodule. Besides the spherules on which the copper is deposited, there are others generally of a larger size and dark colour. These are, so far as microscopic examination shows, quite like the particles on the mammillated outer surface of this Cape meteorite, also from Sir Wyville's collection.

These spherules have hitherto only been noticed in those deposits in deep water far from land, and where for many reasons we believe the rate of formation of deposits to be very slow.

They occur also only in those manganese nodules which come from the same deep-sea clays or deposits far from land.

The particles of native iron found in pumice-stones are not numerous, and never take the form of spherules so far as observed. Some of these particles of native iron may then come from the dredge. Other particles come from the pumice and the volcanic materials. Professor Andrews long since showed that minute particles of native iron existed in basalt and other rocks. And lastly the spherules of which I have been speaking appear to have a cosmic origin.

The reason, for these spherules occurring only in deposits far from land and in deep water, may be more apparent by reference to the annexed diagram, which might represent a section from the west coast of South America out into the Pacific 500 miles. Along the shores of the continent as at a we have an accumulation of river and coast detritus. At b in depths from 1400

VOL. IX.

2 M

to 2200 fathoms we have a globigerina ooze mostly made up of surface shells. At c, in a depth of 2300 to 3000 fathoms, all the surface shells are removed from the bottom. No coast detritus reaches this area, and we find in the deposit pumice stones, some volcanic ashes, manganese nodules, sharks' teeth, and ear bones of whales. It is only in areas like this that we find sharks' teeth and ear bones of cetaceans in any numbers. Some of them from the same haul are deeply surrounded with manganese deposit, and contain little animal matter; while others have no deposit on them, and seem quite recent. These, and other facts which might be mentioned, all argue for an exceedingly slow rate of deposition. Now it is in these same areas that the spherules of native iron and other magnetic spherules are found, both in the deposits and in the manganese nodules from them.

Finding them in this situation favours the idea that they are of cosmic origin, for in such places they are least likely to be covered up or washed away. It is certainly difficult to understand why the spherules on which the copper is precipitated have not become oxidised. If nickel be present in them, this may retard oxidation to some extent.

The manganese depositions in our ocean deposits are very different in structure and composition from any of the ores of manganese I have had an opportunity of examining, and the deposits of the deep sea far from land have not, so far as I know, any equivalents in the geological series of rocks.

All the subjects treated of in this paper are still under investigation, and at some future time I hope to present a much more detailed account.

These observations seem to me to give ground for the following conclusions:

First, That volcanic debris, either in the form of pumice stones, ashes, or ejected fragments, are universally distributed in ocean deposits.

Second, That pumice stones are continually being carried into the sea by rivers and rains, and are constantly floating on the surface of the ocean far from land.

Third, That the clayey matter in deposits far from land is principally derived from the decomposition of the feldspar in fragmental volcanic rocks, though in the trade wind region of the North Atlantic the dust of the Sahara contributes much material for clay.

Fourth, That the red earth of Bermuda, Bahamas, Jamaica, and other limestone countries, is most probably originally derived from the decomposition of pumice stone, while these limestones were in the process of formation.

Fifth, That the peroxide of manganese is probably a secondary product of the decomposition of the volcanic rocks and minerals present in the areas where the nodules of manganese are found.

Sixth, That there are many minute particles of native iron in deposits far from land; that some of these particles are little spherules; that these last, as well as some other spherules which are magnetic, have probably a cosmic origin.

Seventh, That the peroxide of manganese depositions in the deep sea are different in structure and composition from known ores of manganese.

Eighth. That we do not appear to have equivalents of the rocks, now forming in the deep sea far from land, in the geological series.

In conclusion, I have to acknowledge much assistance in these investigations from all my colleagues, especially my indebtedness to Sir Wyville Thomson and Mr Buchanan.

Since my return I have received many hints from Professors Tait, Geikie, Turner, Dr Purves, Mr Morrison, and other gentlemen.

In much of the mechanical work which an examination of these deposits has entailed, I have, both during the cruise and since my return, had the assistance of Frederick Pearcey.

4. On New and Little-known Fossil Fishes from the Edinburgh District, No. I. By R. H. Traquair, M.D., F.G.S.

FAMILY PALEONISCIDÆ.

GENUS Nematoptychius, Traquair, 1875.

This genus was instituted by the author for the reception of the Pygopterus Greenockii of Agassiz, and characterised in the "Annals and Magazine of Natural History" for April 1875. It differs from Pygopterus in the form of the scales of the flank, which are much higher than broad, and having their articular spine arising from the whole, or nearly the whole of the upper margin; in the structure of the pectoral fin, in which all the rays are articulated for the greater part of their extent; and in the form of the anal, which is in shape like the dorsal, and is not produced backwards in the peculiar fringe-like manner characteristic of Pygopterus.

Since the publication of the notice above referred to, remains of N. Greenockii have turned up in two other localities near Edinburgh, viz., near Juniper Green in the horizon of the Wardie Shales (Museum of Science and Art), and at Raw Camps, near Mid Calder, in that of the Burdiehouse Limestone (Collection of the Geological Survey of Scotland).

The following is new to science.

Nematoptychius gracilis, sp. nov. Traquair.

The

Of this two specimens have occurred at Gilmerton. more perfect of these, compressed on its side, displays the entire contour of the fish, including all the fins, and measures 9 inches in total length, by 11 inch in depth between the head and the ventrals; the length of the head is contained about 4 times in the total. The ventral fins arise opposite a point 3 inches distant from the tip of the snout; the commencement of the anal is midway between that of the ventral and of the caudal; the dorsal is situated nearly opposite the anal, commencing only inch in front of it. The form of the fish is thus elongated and slender, gradually tapering from behind the shoulder towards the tail, the dorsal fin being situated very far back. The other and slightly longer spe