having dredged for several years at Madeira, confirms Macandrew's generalisation of the Mediterranean character of the Molluscaexcludes 12 of Macandrew's named list as having crept in by mistake, and to the 115 remaining species identified by Macandrew as Madeiran has added 200 to 250 more, making nearly 400 in all, of which 80 or perhaps 100 are probably new. These he hopes soon to publish.

2. Note on a New Fossil Foot-Print from the Permian Sandstone of Dumfriesshire. By Patrick Dudgeon, Esq., F.R.S.E. (Plate I.)

What appears to be an entirely new foot-print has lately been found in the red sandstone of this district. I have seen many of the foot-prints from the various quarries in the neighbourhood, but have not before observed this one, nor is it like any figured in Sir William Jardine's splendid work on the "Ichnology of Annandale." The foot-prints in question were found in a bed about 20 feet from the surface, at Locharbrigg's Quarry, three miles from Dumfries. They exhibit the usual large hind and smaller fore foot; the impression of the hind foot measures '5 × 2'6, the fore foot 2'3 x 1'-9; the stride of the animal appears to have been about 10. The impression of the hind foot does not interfere with that of the fore foot, as is the case with several of the foot-prints figured in Sir William Jardine's work, the interval between them being 2' the hind foot, therefore, must have been put down in the rear of the fore foot when the animal was walking. The impression of the foot shows five toes, the thumb being placed far back. The most characteristic features in these foot-prints are the welldeveloped claws, and the oblique position of the toes, i.e., they are placed to march one behind the other. In almost all the footprints I have seen, where the toes can be made out, the middle one appears the most prominent; this foot-print is markedly distinct in this respect.

As yet I have only been able to obtain one good specimen of this foot-print-a hind foot; the rest of the slab on which the casts were impressed was unfortunately used for a paving stone in a cottage in the neighbourhood. I got it lifted; but the rough

usage it had been subjected to had greatly injured the impressions on it; they were, however, sufficiently distinct to enable me to give the above particulars.

The accompanying photograph is a good one of the hind foot in my possession, about half the size of the original. The posterior pad of the foot is not quite complete, and it, together with the pads of the toes, are somewhat broken.

I would propose for these foot-prints the provisional name of Herpetichnus loxodactylus, the oblique-toed Herpetichuus, with the following abbreviated character:

GENUS HERPETICHNUS, Jardine ("Ichnology of Annandale," 1853, p. 14).

Herpetichnus loxodactylus, sp. nov.

Sp. chars.-Fore foot 2'3 x 1'9; hind foot = 3'5 x 1'6; stride about 10'; impressions free; toes 5, oblique; thumb far back; claws well developed.

Locality and horizon.-Permian Sandstone, Locharbriggs Quarry, three miles from Dumfries.

P.S.-In the discussion which followed this paper, Professor Huxley stated that so far as he could judge from the photograph exhibited, the markings closely resembled a foot-print he had described some years before in a paper read before the Geological Society of London, "On the Stagonolepis Robertsoni (Agassiz) of the Elgin Sandstones; and on the recently discovered Foot-marks in the Sandstone of Cummingstone" ("Quart. Jour. Geol. Soc.," 1859, xv. p. 440). The resemblance of these Cummingstone footmarks to the Chelichnus of the Dumfriesshire flags was noticed by Professor Huxley in the paper referred to.

3. On the Decennial Period in the Mean Amplitude of the Diurnal Oscillation and Disturbance of the Magnetic Needle and of the Sun-spot Area. By J. A. Broun, F.R.S.

(Abstract.)

The author, in presenting results relating to the decennial period derived from observations made at Trevandrum during twenty-two years, has sought a redetermination of the mean duration of that

period, as shown by preceding magnetical observations connected with his own. The relation of the frequency and area of sun-spots to the amplitude of the diurnal movements of the magnetic needle gives an increased value to this investigation.

Two very different results have been obtained ;-one by Dr Lamont, showing a period of 10-4 years; the other, by Dr R. Wolf, gives 11 years. Dr Lamont's result depends on the assumption that three periods occurred between 1787 and 1818-an assumption which is opposed to the conclusions which have been deduced from the sun-spot, auroral, and magnetic observations for that interval. Dr Wolf's result has therefore been accepted very generally by many of the most eminent scientific men in England and on the Continent.

The author determines the epochs of maximum and minimum range of the diurnal oscillations of the magnetic needle by the more exact method, in which the mean for twelve months corresponding (at its middle point) to each month of the year is obtained. Commencing with the Trevandrum observations, from the present time, proceeding backwards to the earliest series, showing a maximum, that of Cassini (Paris 1784-1788.) The maximum at this time (1787-25) is confirmed nearly by Gilpin's observations (London, 1786-1806). The latter do not show the minimum in 1792 and maximum in 1797, which should satisfy Dr Lamont's assumption, and they are considered by him, like the observations of sun-spots at the time, as worthless for this investigation. Dr Wolf, on the other hand, finds support in both for a minimum in 1798.

It is concluded by the author, from an examination of Gilpin's observations, that a maximum really happened in 1797-7, but so little marked as to make it probable that any slight corresponding increase of sun-spots would not be noticed by the single, not very accurate, observer at the time. Evidence, however, of a slight maximum is also found in Professor Loomis's investigation for the frequency of the aurora borealis. As it is certain that another maximum occurred about 1804 to 1806, the author finds that Gilpin's observations, which agreed with Cassini's at the commencement of the series, showed in all probability the true magnetic variations afterwards.

It results from these investigations that the mean duration of the