fact most of the higher grounds and heaths present myriads of myriads, and in the other parts of the country they are scattered, but not so plentifully. In the deep vales of the Cray and Darent they are wanting.

There is one spot beyond the boundaries above described, where such flints are exceedingly abundant, which is the hill immediately above the firestone quarries, a mile north from Godstone Green.

The best place near London where these flints may be seen to advantage, is at the top of Blackheath hill, immediately in front of the Green Man hotel. One single view of such a collection as is there will give a better idea than any description.

As to size, many of the Blackheath flints are not larger than pease and beans, and by such designation they are known to builders and plasterers. The greater part are however larger, from a pigeon's egg to a hen's egg, and a small proportion of them are even as large as a swan's egg, only rather flattened. The colour on the exterior is sometimes blue, but it is generally of a brownish or rusty appearance.

The form of Blackheath flints is uniformly a flattened ellipsoid. The perfect sameness of form is perhaps the most remarkable circumstance about them, and suggests the idea of their having acquired it by means of gentle agitation whilst yet in only a soft state.

When broken by the hammer the fracture is not like that of chalk flints, being not nearly so much conchoidal. The appearance is most frequently horny or waxy, with frequently white spots, but it is sometimes reddish, though comparatively seldom.

Blackheath flints are seldom at all affected by long exposure to the air. Countless multitudes of them may be seen on the surface, and near to it in many places within the country where they are found, and have been so exposed for a period to which we can set no limit: yet they have not acquired a white crust nor even any white film making any approach to it. However on the south side of the Addington hills, the sun has produced an effect, and whitened to a small degree the flints exposed to his rays.

This

Blackheath flints may be burnt in the fire, without their exploding, which is seldom the case with other flints. has been attributed to their containing less water than other flints, and it may possibly be so.

After being burnt in the fire the fracture is very rough and uneven, and often appears as if blistered. The colour is a dirty white with a considerable mixture of red produced by

the presence of iron. The adhesion of the flint after being burnt is much less than is the case in chalk flints.

Blackheath flints have never been used by the gun-flint makers. No doubt it is possible to make gun-flints from the larger specimens, but it would be with greater labour than from the finer sorts of chalk flints, and the gun-flints so obtained would be more brittle and less durable.

The Blackheath flints are totally unfit for the porcelain manufacture. If there were no other objection, there is frequently, indeed generally, a portion of oxide of iron on the exterior, which would spoil the colour, and generally oxide of iron is present in the interior also.

The powder also obtained by burning and grinding Blackheath flints, would not be so fine. By burning a few specimens in a common fire, and pounding them in a mortar, and then comparing them with chalk flints, treated in a similar way, the difference will appear most obvious.

The Blackheath flints are admirably adapted from their size, for the purpose of the patent building, after being washed and put in moulds, with lime freshed slacked with hot water, then a solid body is produced of appearance like Portland stone in front, and said to answer exceedingly well.

The small flints called pease and beans are used by plasterers as an ornament to their work. The only other use to which they are applied is that of materials for the roads.

Fossil remains are seldom discovered in the Blackheath flints, if we except certain snail-shaped or leech-shaped bodies, found also in the chalk flints of some districts, supposed to be Alcyonites. I have broken thousands upon thousands in search of other fossils, and until this year without success. On Plumstead common I broke open a flint in which was an impression of a spine; and I broke open another with a very fine impression of a spine at Chiselhurst. Mr. John Alfred Burgon, F.G.S. has found two Echini and a Pecten in flint on Blackheath. Still as compared with the flints of other districts, fossil remains are very rare.

The cause of this very great rarity of fossils in these flints is not very obvious. Most of them are indeed too small to envelope shells or even fragments of shells, but it is far from being the case with them all. It is also obvious that although a large number of small flints, agitated by the waters, would destroy and reduce to powder any shells which might be near them, yet some might notwithstanding escape, and be enveloped in the larger flints, as in the districts in which clay flints abound, as Warley and St. Ann's hill; and it is not unlikely that there was diffused through the water something

unfavourable to the support of animal life, so that at the time when the siliceous matter was deposited in this district, there were few or no shells around which it might aggregate. It is perhaps this matter mixed up with the silex, to which the Blackheath flints owe their peculiar character.

The existence of beds of sand frequently discovered below the Blackheath districts, proves the previous great agitation of the waters, and that also must have contributed to diminish the number of shells, but from their very great rarity some destructive mixture seems to have been the most likely cause.

In breaking open some of the Blackheath flints, masses of red coloured gravel are found enclosed, and where there is no possible opening by which gravel might have penetrated into any hollow part left in the flint at its formation. The flint has aggregated around the gravel, precisely in the same way as in the chalk the flint is often found to have aggregated round a mass of chalk, and to have enclosed it on all sides. Specimens of this sort have been met with at Erith, more frequently than at any other place; but they may be found in other localities also.

ART. IX. Upon the Identity of Hunter's Delphinus bidentatus, Baussard's Hyperoodon Honfloriensis, and Dale's Bottle Head Whale. By WILLIAM THOMPSON, Esq.

BELL in his late work upon the British Quadrupeds and Cetacea, mentions in his preface that further information is required on many points of great interest in the history of the latter, and he instances "the relation of the Hyperoodon of Dale to that of Hunter," and Sir W. Jardine in his volume upon Cetacea, pages 194 to 197, canvasses the question of the identity of Hunter's and Baussard's Cetacean, leaving the matter as it appears to me in greater doubt than ever. Where doctors differ I should have thought it the height of presumption to have introduced my humble opinion, were it not that I have an opportunity of forming a judgment not afforded to either of the eminent naturalists in question. Let me at once then state that I conceive there is not a doubt of the identity of Hunter's and Baussard's specimens, both of which were females, and that I conceive Dale's specimen to be the male of the same species; for though from the figure given on page 493 of Bell's work, it appears to differ from the others in form, being thicker in the shoulder, yet I conceive it does not differ more than the bull does from the cow, or the male lion from the lioness: as regards this last point of mine, however, I confess I have nothing beyond surmise; but the possible

difference in figure of the male and female does not seem to have occurred to either Bell or Jardine. But as far as regards the identity of Hunter's Delphinus bidentatus, and Baussard's Hyperoodon Honfloriensis, my opinion is founded on a specimen of a Cetacean stranded just below the town of Hull last year, which was exhibited for many days here, and the skeleton of which forms now part of the Museum of the Hull Literary and Philosophical Society.

The animal in question before dissection was carefully examined by myself and many others, and due attention paid to the mouth, and before the flesh was removed, every one declared it had no teeth, in this respect it quite agreed with Baussard's specimen of a mother and cub stranded at Honfleur, of which Jardine says, p. 195, " The circumstances on which the claim of these specimens to be considered generic rest, are the total want of teeth in either jaw."

Upon the skeleton of the Hull specimen being prepared, however, on removing the gums "two strong and robust teeth were discovered to exist at the extremity of the lower jaw," though previously covered and entirely concealed by the gums.

Here then we have an animal in its perfect state, agreeing with the creature which Baussard described in a similar state, and also agreeing in its skeleton state, with the skeleton in the Hunterian Museum, described by Hunter; thus, though both are describing the same animal, yet one having seen it in the recent, the other in the skeleton state, each gives a different account as to its teeth, like the far-famed travellers' dispute about the camelion's colour.

In figure the Hull specimen was a fac simile of Jardine's Hyperoodon Honfloriensis, figured plate 13 of his volume, with the exception that the engraver of that plate has inserted two lateral teeth in the upper jaw of the figure; I say the engraver, for I conceive that Sir W.Jardine never authorized their being inserted after describing the generic character of the animal to consist "in its total want of teeth in either jaw." These supposititious teeth in the upper jaw should be immediately erased from Sir W. Jardine's plate, before any more impressions are struck off. The plate in Bell's work p. 492, is also a good resemblance of the Hull whale, though perhaps not so striking a portrait of it as Jardine's, with the exception of the lateral teeth, which do not occur in Bell's plate, rendering it more correct than Jardine's, and less likely to create doubts in the mind of young naturalists.

Speaking of Baussard's whales, (mother and cub), Sir W. Jardine says "Bounaterre in describing the individuals exa

mined by him, most unaccountably assigned to them two teeth in the lower jaw." Now I think it is well accounted for thus; Bounaterre described the skeletons; Baussard the animals with their flesh on; this very circumstance agreeing with the one I have described at Hull, shews that the Honfleur specimens were identical in species with the Hull one; and since the Hull one in its skeleton state, quite corresponds with the Hunterian specimen, it follows that Hunter's and Baussard's specimens are also of the same species,-in short, that Baussard's specimen, Hunter's specimen, and the Hull specimen, are all specimens of Hyperoodon honfloriensis.

The skull of the Hull specimen corresponds in its general form, with the one figured in Bell's work, although the rise in the back part of the head is larger in proportion to the anterior rise, than that figured by Bell, as the following measurement will shew, viz:

From the snout to the base of the front rise of the skull......... From the base of the front rise, across that rise to the base of) the second rise......

From the base of second rise across that rise to its base next the neck

......

ft. in.

09

1 0

1 11

The total length of the animal skeleton, from snout to tail, 17 ft. 6in. the lower jaw extending two inches further. When alive however it was considerably longer, owing to its fleshy tail extending beyond the last of the caudal vertebræ and owing to the loss of much intervertebral matter.

Vertebræ 39, viz. 2 cervical, 9 dorsal, with dorsal processes and ribs attached, 20 dorsal, without ribs, but with dorsal processes, 8 caudal, without any dorsal processes.

Should these observations at all assist in elucidating the point Mr. Bell states to require elucidation, I shall be very glad. At all events if my own remarks prove useless, the information where another specimen may be examined by able naturalists must have some utility.