this case there is a very interesting fossil relic of this kind— the half of the lower jaw of a gigantic animal allied to the existing genus Castor, which was discovered by the Rev. J. Green, in a lacustrine deposit of clay and sand at Ostend, near Bacton, on the coast of Norfolk; a locality which has yielded remains of mammoths, deer, roe-bucks, large watermoles, &c.'

The incisor (which is longer and stronger than in the existing Beavers), the molar teeth, and the articulation of the jaw, are beautifully displayed in this highly interesting British example of a gigantic extinct rodent, whose relics were first discovered in Russia, a cranium having been found by M. Fischer, on the borders of the Sea of Azof, in 1822.2 original was probably about one fifth longer than the common species of Beaver. The skull and jaws of a much larger rodent related to the Castor, has lately been discovered in the

The

LIGN. 74.-LOWER JAW OF AN EXTINCT GIGANTIC BEAVER, FROM OSTEND, NORFOLK. ( nat. size.)

alluvial deposits that contain the remains of Mastodons, in the State of Ohio. An admirable memoir on this cranium has been published by the eminent American palæontologist, Dr. Jeffries Wyman. The name of Castoroides Ohioensis has been given to this colossal beaver; the entire length of the original

See Professor Owen's elegant and interesting "History of British Fossil Mammals," p. 25.

2 Described by Baron Cuvier, under the name of Castor Trogontherium, "Oss. Foss." Vol. v. Part I. p. 59.

animal is estimated at twice that of the existing species, viz. five feet.1

GLYPTODON.-Wall-case G.-In the lowermost compartment of this case, there are two remarkable relics of colossal edentate animals allied to the Armadillos, to which I would direct the visitor's attention; but it will be convenient to reserve an account of the geological conditions in which these and similar remains occur, till the skeletons of gigantic animals of this order in Room VI. come under

examination.

I will, therefore, only remark that these fossils are the osseous dermal cases, or sheaths, of the tails of two distinct species of Glyptodon; an animal somewhat resembling the Armadillo, being covered with a coat of mail, formed of polygonal osseous plates, united by sutures, that constituted an impenetrable covering to the body. The plates of this bony investment were not disposed in rings, as in the Armadillos, but were articulated to each other, and formed a tesselated cuirass; the tail was inclosed in a case of this kind, like a sword in its scabbard.2

LIGN. 75. THE OSSEOUS DERMAL CASE

OF THE TAIL OF A

One of the specimens in the British Museum appears to belong to the species named Glyptodon clavipes; but the other (see Lign. 75), which is nearly three feet in length, is remarkable for the expanded lobes near the distal termination of the tail. DON (nat. size.) These fossils are deserving of particular examination; they will, I presume, sooner or later, be placed in Room VI. with the other remains of the Edentata of South America."

1" Boston Journal of Nat. Hist." 1846.

SPECIES OF GLYPTO

2 A splendid specimen of the bony cuirass of the Glyptodon is in the Hunterian Museum of the Royal College of Surgeons, in London.

3 A restored figure of the Glyptodon forms the frontispiece of the highly interesting work on "Buenos Ayres and the Province of Rio de la Plata," by Sir Woodbine Parish, K.C.H. &c.; the indefatigable explorer, to whom science is indebted for the most important examples of the extinct colossal Edentata hitherto brought to Europe.

CHAPTER IV.

PART I.

PLAN OF ROOM IV.-SYNOPSIS OF CONTENTS-ICHTHYOSAURI COLLECTED BY MR. HAWKINS-ICHTHYOSAURUS TENUIROSTRIS-I. INTERMEDIUS-I. LONGIPENNIS-I. COMMUNIS-I. PLATYODON-I. LONCHIODON-I. LONGIROSTRISFOSSIL REMAINS OF RUMINANTS FOSSIL CARNIVORA OF THE CAVERNSMACHAIRODUS-FOSSIL MAMMALIAN FROM STONESFIELD-MINERALS-UNIVALVE SHELLS OF THE OOLITE AND CRAG-FOSSIL ZOOPHYTES.

THE Wall-cases A, B, C, D, E, on the south or left side of Room IV., like those in the apartment we have just surveyed, are assigned to fossil remains of reptiles, and contain a noble collection of ICHTHYOSAURI, from the liassic deposits of England. With but few exceptions, these splendid specimens were obtained and developed by Thomas Hawkins, Esq. of whom they were purchased by the Trustees of the British Museum, together with the unrivalled series of Plesiosauri described in the former chapter.

A collection of bones of ruminants from the alluvial deposits of the valley of the Thames, chiefly from Grays and Ilford in Essex, is deposited in Wall-case F. It comprises some fine skulls, jaws with teeth, and bones of the extremities, of several species of Bos or Ox, Deer, &c.

In Wall-case G, there is a considerable number of very perfect crania, jaws with teeth, &c. of extinct species of Bears, from the ossiferous caves of Gailenreuth, in Germany; and a most interesting and precious fossil relic-the half of the lower jaw of a small terrestrial mammalian, from the lower Oolite of Stonesfield.

Besides the fossils above specified, there are many species and genera of tertiary and secondary univalve shells, and

corals and other zoophytes, which occupy three Table-cases. The other cabinets contain minerals only.

These numerous and diversified objects will be noticed under the following sections; viz.-I. Synopsis of Contents. II. The Ichthyosauri. III. Fossil remains of Ruminants. IV. Fossil Carnivora of the Caverns. V. The Fossil Mammalian of Stonesfield; and VI. the collections of Shells and Zoophytes of the last, a brief notice only is within the scope of the present volume.

:

ROOM IV.

(62 feet long.)

SYNOPSIS OF CONTENTS.

ORGANIC REMAINS.

WALL-CASES: these contain a fine suite of Ichthyosauri, from the Lias formation of England.

A. [1.] Specimens of

Ichthyosaurus tenuirostris.

intermedius.

longipennis.

communis.

In one specimen coprolites are seen in the abdominal space. Ichthyosaurus platyodon.-There is a very large and fine skull and jaws of this species, with the osseous plates of the sclerotica perfect, and part of the spinal column.

B. [2.] Two specimens of Ichthyosaurus intermedius.

On a slab of Lias limestone there is a fine Ichthyosaurus, with the spine in an arched position, and the four paddles nearly entire; from Street, Somersetshire.

There are in this compartment many small examples of paddles, and other detached parts of Ichthyosauri.

C. [3] In this Case is a noble skeleton of Ichthyosaurus platyodon, eighteen feet long; and a small and beautiful Ichthyosaurus, presented by Mr. Broderip.