examples of the tripod class in all Cornwall, viz. those of Lanyon and Caerwynen, and those are both modern restorations of dilapidated ruins: not a single stone of either of these examples is as it originally stood "in situ." I did not see Mr. Borlase's letter to NATURE until the 3rd inst. On the 5th I obtained old Dr. Borlase's quaint volume on the "Antiquities Historical and Monumental of the County of Cornwall" (2nd ed. 1769), from a chapter in which volume Mr. Fergusson borrows his title of "Rude Stone Monuments," and on the following day visited Lanyon Quoit itself, sketched it, and compared the accounts of it on the very spot, and the following is the result of my investigation. I will take Mr. Borlase's statements categorically :(1) Lanyon Quoit "always was, as it is now, a freestanding dolmen."

:

(1) I humbly submit that Lanyon Quoit could not possibly have been always as it is now, from the fact of its having fallen, during a violent storm in 1815, whilst a comparison of its plan, as it now is in its restored state, and as it is given by Dr. Borlase, shows that the stones have been moved. The supporters were originally parallel, and are now at different angles to one another.

(2) "A tripod dolmen consisting of three slim pillars supporting on their summits a horizontal stone."

(2) I leave it to my readers to judge from the accompanying representation (from a photograph) of the cromlech whether, from the flat nature of the component stones, the supporters have not more or less the character of slabs rather than that columnar shape necessary for the so-called "Table stone proper:" and whether the three slim pillars would not have been more accurately described as stout stone slabs. The good Rector of Ludgvan, more than a hundred years ago, more aptly described these Cornish monuments.* "Three or four large flags or thin stones capped with a much larger one, which go by the British name of cromlêhs;" and again, "In several parts of Cornwall we find a large flat stone in a horizontal position (or near it) supported by other flat stones fixed on their edges and fastened in the ground." He never mentions pillars or columnar supports.

Mr. Borlase omits to mention the fourth slab (D) which is prostrate to the north (see plate), and the fifth and sixth flat stones (E and F) (possibly one broken in two) which lie imbedded in the soil at the foot of the south supporter, in which position they were apparently placed by the restorers in 1824 to prop up the upright slab. †

(3) Two drawings of it in its pristine condition by Canon Rogers, 1797, and Dr. Borlase, 1747, "agree in representing the slimness of the pillars, their distance apart, and great height of monument, features which render it not unlike a gigantic three-legged milking-stool."

Dr. Borlase's drawing shows four upright slabs, although the fourth does not apparently touch the capstone. I think that the supporters A, B, C, may be identified with those in Dr. Borlase's drawing with tolerable certainty, and D, now prostrate, was the fourth upright that E and F were once also upright is highly probable.

(4) Then, as now, there was no mound about it. It stood on a low bank of earth and the area had been often disturbed by treasure-seekers."

(4) Dr. Borlase says "this cromlêh stands on a low bank of earth not two feet higher than the adjacent soil, about 20 feet wide and 70 feet long." The cromlech stands as much in as on the long mound which, according to the above measurements, would contain at least 2,000 cubic feet of earth, besides the many rough stones not the natural furniture of the place," which Dr. Borlase also mentions. It bears every appearance of having formed the base of a long barrow.

66

(5) "No houses are near it which could have received the stones of a denuded mound."

(5) A good road with rough stone walls on each side of it, which runs within a few yards of the cromlech, would well account for a portion of a denuded mound or cairn whose stones would be well adapted for building the walls and metalling the road.

(6) "It is difficult to see how a kist-vaen or septum of any kind could have been formed beneath the cap-stone. Had a wall of small stones been built from pillar to pillar the height of the superincumbent mound must have forced them inwards, a catastrophe which the "dolmen-builders” were always careful to avoid."

(6) Mr. Borlase must have had experience in his researches among the underground bee-hive caves to know how extensively microlithic dry masonry can be so built up as to resist any outside pressure of a superincumbent mound.

(7) "Had large stones placed on edge formed the walls of the kist, how is it they are all removed, while every other cromlech in the district retains them ?"

(7) In "Nænia Cornubiæ," p. 43, Mr. Borlase writes, with regard to Lower Lanyon Cromlech, "Two stones are all that now remain, viz. the covering stone and one of the supporters; the others having been split up and carried away for building."

(8) "My strongest proof is yet to come. The interment was not in the kist at all. A grave had received the body six feet under the natural surface of the surrounding soil, and within the area described by the structure. This being the case, of what use could an enclosed kist have been, or why should the cenotaph be covered in at all?"

(8) Dr. Borlase discovered a pit within the area of the kist-vaen of Mulfra Quoit; and Mr. Borlase himself relates in his Nænia "a small pit seems to have been sunk in the centre" of Chywoone cromlech which he acknowledges was buried in a tumulus. This method of interment would therefore seem common to these three structures.

(9) "On the southern side of the structure, and so near it that a mound over the monument must have inevitably covered it up, stands a little circular ring cairn of the ordinary type, in the centre of which I found the remains of an inner ring which, though now rifled, had doubtless contained an interment."

(9) Dr. Borlase mentions with regard to the long low bank above-mentioned" at the south end, has (sic) many rough stones, some pitched on end, in no order; yet not the natural furniture of the surface, but designedly put there; though by the remains, it is difficult to say what their original position was.”

Should Mr. Borlase's recognition of the confused aggregation of stones as a ring cairn be correct, it is by no means inconsistent with the theory that a mound once enveloped the cromlech and (as Mr. Borlase suggests would be the case) included the ring cairn in its area.

A parallel case occurs at Moustoir Carnac in Brittany, a plan and section of which, after M. Galles, is given in Fergusson's work, p. 358, and which I have personally examined. Here we find a true dolmen, two ring cairns, and a kist within one large long tumulus or barrow.

From my own inspection, I agree with the older Borlase, that "nothing is to be absolutely concluded, there having happened so many disturbances," but I have little doubts that whatever it was it formed some part of a structure in connection with and belonging to the cromlech.

Whilst comparing Cornish cromlechs with French dolmens, a comparison should be made between Chywoone cromlech and Mr. Fergusson's characteristic example at Grandmont† in Bas-Languedoc (woodcut No. 128), with regard to which he says, "The umbrella form is hardly

* Nænia Cornubiæ, p. 55.

Rude Stone Monuments," pp. 343, 344. Figured in NATURE, vol. v, p. 387.

NOTES FROM THE "CHALLENGER"

VI.

E left Bermudas on Thursday, June 12, for the Governor of the Island, with his private secretary, Capt. Trench and Capt. Aplin, R.N., Captain Superintendent of the Dockyard, and a party of ladies, came on board in the afternoon, and we bade farewell, with great regret, to the friends from whom we had received such unvaried kindness during our stay. At half-past five we steamed out of the Camber and passed among the reefs to Murray's Anchorage, on the north-east side of the island, where we anchored for the night. Next morning we proceeded through the narrows, and early in the forenoon, having seen the last of the treacherous and beautiful purple shadows in the bright green waters of Bermudas, we set all plain sail and stood on our course to Fayal. In the afternoon we got up steam and sounded, lat. 32° 37' N., long. 64° 21′ W., in 1,500 fathoms, with the usual grey-white chalky bottom which surrounds the reefs.

WE Azores. His Excellency Gen. Lefroy, C.B., F.R.S.,

Our position, at noon of the 15th, was lat. 33° 41' N., long. 61° 28′ W., 1,610 miles from Fayal.

On the morning of the 16th we sounded in 2,575 fathoms, the bottom a reddish ooze, containing a large number of foraminifera. The bottom temperature was 1°5 C. A small, rather heavy trawl, with a beam 11 feet long, was put over in the morning, but when it was hauled in, about five in the afternoon, it was found that it had not reached the bottom. This was the first case of failure with the trawl. It was probably caused by the drift of the ship being somewhat greater than was supposed. The net contained a specimen of one of the singular and beautiful fishes belonging to the Sternoptychidæ, an aberrant family of the Physostomi, distinguished by having on some part of the body ranges of spots or glands producing a phosphorescent secretion. The surface of the body is, in most of the species, devoid of scales, but, in lieu of them, the surface of the skin is broken up into hexagonal or rectangular areæ, or separated from one another by dark lines, and covered with a brilliant silvery pigment, dashed with various shades of green or steel blue. We have taken, in all, four or five species of these fishes, all in the net, when dredging or trawling, at great depths. I do not think they come from the bottom, however. It seems more probable that they are caught in the net on its passage to the surface, possibly at a depth of two or three hundred fathoms, where there is reason to believe there is a considerable development of a peculiar pelagic fauna.

On Tuesday, the 17th, the trawl was lowered at seven in the morning, and in the forenoon a sounding was taken in 2,850 fathoms.

Several examples of a large and handsome species of the genus Scalpellum came up in the trawl, a few still adhering to some singular-looking concretionary masses which they brought up along with them. One of these lumps, to which a large example of the barnacle was attached, was irregular in form, about three centimetres in length, and two in width. The surface was mammellated and finely granulated, and of a dark-brown colour, almost black. A fracture showed a semi-crystalline structure, the same dark-brown material arranged in an obscurely radiating manner from the centre, and mixed with a small quantity of a fragment of greyish-white clayey matter. This nodule was examined by Mr. Buchanan, and found to consist, like the nodules dredged in 2,435 fathoms at Station 16, 700 miles to the east of Sombrero, almost entirely of peroxide of manganese. Some other concretionary lumps were of a grey colour, but all of them contained a certain proportion of pyrolusite, and they seemed to be gradually changing into nodules of pyrolusite by some process of alteration or substitution. This is undoubtedly very singular, and it is

difficult to conceive what can be the source of so wide

spread a formation of manganese. It is, of course, a

matter of great difficulty to make anything like accurate analyses on ship-board. Mr. Buchanan is giving his careful attention to the whole subject of the chemical composition of the sea-bed, and I hope that the determination of the composition of a number of samples, when a favourable opportunity occurs, will throw additional light upon this and a number of other obscure points connected with the chemistry of modern geological formations.

Scalpellum regium, n. sp. (Fig. 1), is by far the largest of the known living species of the genus. The extreme length of a full-sized specimen of the female is 60 mm., of which 40 mm. are occupied by the capitulum, and 20 mm. by the peduncle. The capitulum is much compressed, 25 mm. in width from the occludent margin of the scutum to the back of the carina. The valves are 14 in number; they are thick and strong, with the lines of growth strongly marked, and they fit very closely to one another,

FIG. 1.-Scalpellum regium, Wy. Thomson. a, Males lodged within the edge of the scutum. FIG. 2.-Male of Scalpellum regium.

in most cases slightly overlapping. When living, the capitulum is covered with a paie-brown epidermis, with scattered hairs of the same colour.

The scuta are slightly convex, nearly once and a half as long as broad. The upper angle is considerably prolonged upwards, and, as in most fossil species, the centre of calcification is at the apex. A defined line runs downwards and backwards from the apex to the angle between the lateral and nasal margins. The occludent margin is almost straight. There is no depression for the adductor muscle, and there is no trace of notches or grooves along the occludent margin for the reception of the males; the interior of this valve is quite smooth. The terga are large, almost elliptical in shape, the centre of calcification at the upper angle. The carina is a handsome plate, very uniformly arched, with the umbo placed at the apex. Two lateral ridges, and a slight median ridge run from the umbo to the basal margin. The lower part of the valve widens out rapidly, and the whole is deeply concave. The rostrum, as in Scalpellum vulgare, is very minute, entirely

hidden during life by the investing membrane. The upper latera are triangular, the upper angle curving rather gracefully forwards; the umbo of growth is apical.

The rostral latera are long transverse plates lying beneath the basal margins of the scuta. The carinal latera are large and triangular, with the apex curved forwards very much like the upper latera, and the inframedian latera are very small, but in form and direction of growth nearly the same.

The peduncle is round in section and strong, and covered with a felting of light-brown hair. The scales of the peduncle are imbricated and remarkably large, somewhat as in S. ornatum Darwin. About three, or at most four scales, pass entirely round the peduncle. The base of attachment is very small, the lower part of the peduncle contracting rapidly. Some of the specimens taken were attached to the lumps of clay and manganese concretions, but rather feebly, and several of them were free, and showed no appearance of having been attached. There is no doubt, however, that they had all been more or less securely fixed, and had been pulled from their places of attachment by the trawl. On one lump of clay there were one mature specimen and two or three young ones, some of these only lately attached. The detailed anatomy of this species will be given hereafter, but the structure of the soft parts is much the same as in Scalpellum vulgare.

In two specimens dissected there was no trace of a testis or of an intromittent organ, while the ovaries were well developed; I conclude, therefore, that the large attached examples are females, corresponding, in this respect, with the species otherwise also most nearly allied, S. ornatum. In almost all the specimens which were procured by us, several males, in number varying from five to nine, were attached within the occludent margins of the scuta, not imbedded in the chitinous border of the valve, or even in any way in contact with the shell, but in a fold of the body-sac quite free from the valve. They were ranged in rows, sometimes stretching as in one case where there were seven males on one side--along the whole of the middle two-thirds of the edge of the tergum.

The male of Scalpellum regium (Fig. 2) is the simplest in structure of these parasitic males which has yet been observed. It is oval and sac-like, about 2 mm. in length by 9mm. in extreme width. There is an opening at the upper extremity which usually appears narrow, like a slit, and this is surrounded by a dark, well-defined, slightly raised ring. The antennæ are placed near the posterior extremity of the sac, and resemble closely in form those of S. vulgare. The whole of this sac, with the exception of a small bald patch near the point of attachment, is covered with fine chitinous hairs arranged in transverse rings. There is not the slightest rudiment of a valve, and I could detect no trace of a jointed thorax, although several specimens were rendered very transparent by boiling in caustic potash. There seems to be no œsophagus nor stomach, and the whole of the posterior two-thirds of the body in the mature specimens was filled with a lobulated mass of sperm-cells. Under the border of the mantle of one female there were the dead and withered remains of five males, and in most cases one or two of the males were not fully developed; several appeared to be mature, and one or two were dead, empty, dark-coloured chitine sacs.

On Wednesday, June 18, we resumed our course with a fine breeze, force 5 to 7, from the south-east. In this part of our voyage we were greatly struck with the absence of the higher forms of animal life. Not a sea-bird was to be seen, with the exception of a little flock of Mother Carey's chickens, here apparently always Thalassidroma wilsoni, which kept playing round the ship, on the watch for food, every now and then concentrating upon some peculiarly rich store of offal as it passed astern, and staying by it while the ship went on for a quarter of a mile,

fluttering above the water and daintily touching it with their feet as they stooped and picked up the floating crumbs, and then rising and scattering in the air to overtake us and resume their watch.

The sea itself in the bright weather, usually under a light breeze, was singularly beautiful-of a splendid indigo-blue of varying shades as it passed from sunlight into shadow, flecked with curling white crests; but it was very solitary day after day went by without a single creature (shark, porpoise, dolphin, or turtle) being visible. Some gulf-weed passed from time to time, and bunches of a species of Fucus, either F. nodosus or a very nearly allied form, evidently living and growing, and participating in the wandering and pelagic habits of Sargassum. The floating islands of the gulf-weed, with which we have become familiar as we have now nearly made the circuit of the "Sargasso Sea," are usually from a couple of feet to two or three yards in diameter, sometimes much larger; we have seen, on one or two occasions, fields several acres in extent, and such expanses are probably more frequent nearer the centre of its area of distribution.

They consist of a single layer of feathery bunches of the weed Sargassum bacciferum, not matted together, but floating nearly free of one another, only sufficiently entangled for the mass to keep together. Each tuft has a central brown thread-like branching stem studded with round air-vesicles on short stalks, most of those near the centre dead, and coated with a beautiful netted white polyzoon. After a time vesicles so encrusted break off, and where there is much gulf-weed the sea is studded with these little separate white balls. A short way from the centre, towards the ends of the branches, the serrated willow-like leaves of the plant begin, at first brown and rigid, but becoming, farther on in the branch, paler, more delicate, and more active in their vitality. The young fresh leaves and air-vesicles are usually ornamented with the stalked vases of a Campanularia. The general colour of the mass of weed is thus olive in all its shades, but the golden olive of the young and growing branches greatly predominates. This colour is, however, greatly broken up by the delicate branching of the weed, blotched with the vivid white of the encrusting polyzoon, and riddled by reflections from the bright blue water gleaming through the spaces in the network. The general effect of a number of such fields and patches of weed, in abrupt and yet most harmonious contrast with the leaves of intense indigo which separate them, is very pleasing.

These floating islands have inhabitants peculiar to them, and I know of no more perfect example of protective resemblance than is shown in the gult-weed fauna. Animals drifting about on the surface of the sea with such scanty cover as the single broken layer of the seaweed, must be exposed to exceptional danger from the sharp sea-birds hovering above them, and from the hungry fishes searching for prey beneath, but one and all of these creatures imitate in such an extraordinary way, both in form and colouring, their floating habitat, and consequently one another, that we can well imagine their deceiving both the birds and the fishes. Among the most curious of the gulf-weed animals is the grotesque little fish, probably Antennarius marmoratus, which finds its nearest English ally in the "fishing frog" (Lophius piscatorius), often thrown up on the coast of Britain, and conspicuous for the disproportionate size of its head and jaws, and for its general ugliness and rapacity. None of the examples of the gulf-weed Antennarius which we have found are more than 50 mm. in length, and we are still uncertain whether such individuals have attained their full size. It is this little fish which constructs the singular nests of gulf-weed bound in a bundle with cords of a viscid secretion, which have been already mentioned as abundant in the path of the gulf-stream.

Scillaa pelagica, one of the shell-less mollusca, is also a frequent inhabitant of the gulf-weed. A little short