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mammary glands, altogether disregards the consideration of their viviparous production, and must, in strict logicał acceptation, be taken to include all animals possessing these organs, even when the function, which they were originally designed to execute, no longer exists: for, in the progressive degradation of organic perfection, through successive groups, it is a necessary condition of existence itself, that the function should cease, either simultaneously with the organ, or before it is obliterated; and this latter phenomenon is so universally the case with regard to all other organs and functions, that it ought not to be accounted matter of surprise in the present instance.

The Monotremata must therefore be regarded as a subordinate group of mammals, but whether of primary or of secondary value, whether entitled to rank as an order or only as a family, is an inquiry which admits of more reasonable doubt. For my own part, as I consider the existence of the marsupial bones to be the simple and only unexceptionable character of the group, to which they are peculiar, I prefer considering the Monotremata as a subordinate group, or family, of this order, rather than elevating them to an independent and equal rank, or associating them with a different order. It is true indeed, that, strictly speaking, they come equally within the definition of M. Cuvier's Edentata, but if approximated to this order rather than to the other marsupials, the integrity and logical simplicity of the latter group is. destroyed; for these, as already observed, depend, not upon the existence of the abdominal pouch, which is not common to all the species of animals included in the present order, but properly upon that of the marsupial bones.

Art. IV.-Illustrated Zoological Notices. By EDWARD CHARLES

WORTH, F.G.S.

(Continued from page 248). 1. On a Specimen of the Lower Jaw of the Mammoth. 2. On a Tooth of the Genus Otodus, Agassiz, from the London Clay. 3. On a Fossil Zoophyte from the Kentish Chalk, inclosing a Cidaris. THE fossil elephant's jaw represented in the accompanying

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appears from this extract that Professor Agardh, like M. De Blainville, is disposed to view the marsupials as forming a distinct class, intermediate between mammals and birds; I have already stated my reasons for dissenting from this opinion.

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Fossil Jaw of Mammoth. to be stila figure (No. 40), was obtained by a Dover fisherman in 1837, whilst dredging off the Dogger Bank; and after having been offered for sale to the British Museum and other metropolitan institutions, was purchased by Mr. G. B. Sowerby, in whose possession it has since remained. It is decidedly the finest relic of the kind that I have seen; and the very faithful representation which I am enabled to publish of it, is due to the skill of Mr. G. B. Sowerby, jun., by whom the drawing on wood was executed.

Аз руина The source from which this noble fossil was derived, the bed of the German Ocean,-is that which has more or less enriched the various museums and private collections throughout the kingdom : indeed the profüsion in which the disjointed skeletons of the larger Pachydermata, must lie strewn over the bed of the sea, along the south-eastern coast of England almost baffles conception. Mr. Samuel Woodward, in his Geology of Norfolk, supposes that upwards of two thousand elephants' grinders had been dredged up by the fishermen off one little village (Hasbro') on the Norfolk coast, in the space of thirteen years; and though he does not supply us with the data upon which he founded

his calculation, his statement may readily be believed when one private collector in that neigh

bourhood,—the Rev. James Layton,--speaks of having had three hundred in his possession."

It would be a matter of great interest to determine the extent of the sub-aqueous area over which these fossil remains are distributed; but conclusions upon this point must be in a great measure merely conjectural, as the necessary evidence can only be obtained where the soundings are sufficiently shallow to admit of dredging being carried forward. Until the finding of this jaw off the Dogger Bank, which is somewhere about midway between the English and Dutch coasts, the greatest distance from the shore where fossil remains had been met with was the Knole Sand. At this spot, which is about twenty miles from the coast, a tusk, weighing ninety-seven pounds, and measuring nearly ten feet in length, was discovered in 1829.

As in the case with the fossil volutes cast on shore near Harwich, the remains of extinct mammals drawn up in the nets of the oyster-dredgers, and which have perhaps reposed for thousands of centuries on the bed of the ocean, are in a much finer state of preservation than those which, in the present day, are so constantly being exhumed in our inland superficial deposits. The mammoth's teeth, instead of falling to pieces as they so frequently do when removed from the soil in which they are imbedded, in the former case will often bear slitting and polishing in the same manner as the teeth of the existing Asiatic elephant. A tusk, taken up off Scarborough about three years since, by some Yarmouth fishermen, was so slightly altered in character, that it was sawn up into as many portions as there were hands in the boat, each man claiming his share of the ivory for economical purposes. In the present specimen, although the teeth are extremely perfect, their condition has more about it than usual of the ordinary character of fossil teeth ; but the firm aspect, and the increased density and compact structure of the bony material of the jaw, would at once arrest the attention of an observer, familiarised only with such osseous remains as are procured under ordinary circumstances.

We cannot suppose this jaw to have been drifted far from the original site of its deposition, for although the condyloid apophyses are gone, if so ponderous a body had been acted upon by the operation of currents, a separation of the rami at the symphysis must have taken place. The detached grinders obtained in a similar way are seldom bouldered, and it is

See Fairholme's Geology of Scripture. Mr. Layton has subsequently removed to Sandwich.

? The portion of this tusk which fell to one of the boat's crew is preserved in the collection of Mr. Robt. Fitch, at Norwich.

therefore probable that as the sea encroached upon the land, these remains, by the gradual falling away of the cliffs, became engulphed, and are now found at the spots where they were in the first instance deposited, although the level which they now occupy is necessarily somewhat lower.

Little or nothing has been added by subsequent writers to the description which the illustrious Cuvier has given us of the osteological peculiarities which serve to distinguish the fossil species of the genus Elephas; and paleontologists still follow him in referring elephantine remains, in whatever region they may be found, to one and the same species. A slighter amount of divergence in the horizontal rami of the lower jaw, accompanied with a change in the shape of the canal formed by the approximation of these parts, especially at its anterior termination ;-grinding teeth wider in proportion to their length, and with more numerous and less festooned laminæ :—are points of distinction referred to by the above-named distinguished anatomist, when comparing the skeleton of the mammoth with that of the Asiatic elephant, the nearest allied of the two existing species. Mr. Sowerby's drawing admirably displays the form of the anterior termination of the canal in the present specimen. It is not nearly so wide as seen in the figures which illustrate Cuvier's observations, but at the same time it differs materially from that of the existing species, which, in the adult skeleton, has more the character of a deep cleft. A short distance from the symphysis the canal contracts to about two-thirds the diameter of its anterior termination, and a somewhat similar contraction is shown in one of the jaws figured in the 'Ossemens Fossiles. The following dimensions may perhaps as well be recorded.

FT. IN. 1 7

Width between the ascending rami at the coronoid processes, Width of each ascending ramus, measured midway between the angle of the jaw and the condyloid apophysis,

10 Width of canal at the anterior termination, ..

3} Ditto ditto five inches from the symphysis, Circumference of the symphysis measured from before to behind,

including the process of the mentum (one inch in length) 1 1 From the above dimensions it appears that the diameter of the anterior termination of the canal, as compared with the expansion of the ascending rami, is in the proportion of 1 to 6: in the two lower jaws figured in pl. 5 tome i. of the Ossemens Fossiles, this proportion is represented as 1 to 4.

I have remarked an extraordinary disproportion in the relative number of plates, when fossil elephants' teeth from North America are compared with teeth from the coast of

Norfolk; those of the former exceeding the latter in the proportion of at least 2 to 1: while I have

noticed that the teeth found in the supposed hyæna's retreats, exhibit a proportion intermediate to these two. I fully anticipate that sooner or later it will be found that several species have been confounded under the name Elephas primogenius.

In the first volume of the new series of this Magazine, p. 226, I have noticed the occurrence of the teeth of a gigantic shark (Carcharias megalodon) in the red crag of Suffolk, and have given an engraving of a particularly fine specimen of that species in the cabinet of Mr. Colchester, of Ipswich.-The name Otodus has been lately applied by Agassiz' to the largest teeth in the family of sharks which occur in the London clay, and the tooth of this genus now figured (41) I believe to be unique as regards size and perfect state of preser

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Tooth of the Fossil Genus Otodus. vation. It was found in the cliffs at Walton, in Essex, by a servant of Lord Sidmouth, and Lady Sidmouth obligingly permitted me to remove it from her cabinet for the purpose of inserting the present notice. In size this tooth presents us with

Figures are given in the last Livraison of the ' Poissons Fossiles, but no descriptive letter-press.

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