Teleosaurus priscus.-Wall-case B.'-The beautiful reptilian fossil thus labelled, is entered in the "Museum Synopsis" as "another species of Gavial, (considered as a distinct genus, by H. von Meyer, to which he has given the name of Eolodon,) from the lias at Monheim in Franconia, being the unique specimen figured and described by Soemmering in the Memoirs of the Academy of Munich, as Crocodilus priscus."3

This specimen is also described by Cuvier (Oss. Foss. tome v. p. 120, pl. VI.) under the name of "Gavial de Monheim.

It consists of a considerable portion of the skeleton of a reptile about three feet in length, imbedded in a layer of yellowish grey calcareous schist; the slab having been split asunder (as in the Swanage specimen), each of the exposed surfaces displays portions of the enclosed osseous remains. On the stone there are casts of discoidal shells, the impression of the tail of a small fish, and remains of insects. quarry whence the specimen was obtained is worked for lithographic stones, and is celebrated for the remains of Pterodactyles, fishes, crustaceans, insects, &c. which we shall notice in the sequel.

The

The following diagram may assist the visitor in identifying the specimen :

2 Indicative of the alternating size of the teeth.

3 Trans. Academy of Munich, 1814.-" CROCODILUS PRISCUS.-Rostro elongato cylindrico, dentibus inferis alternatim longioribus, femoribus dupla tibiarum longitudine."-Soemmering. The description is accompanied by figures of the natural size, of which I have a copy, presented to me by the distinguished author, nearly thirty years since.

The largest slab contains the bones of the head, trunk, and tail of the animal, from one extremity to the other, but little deranged from their natural connections. The skull, however, is twisted over, and the lower jaw lies uppermost in the position in which the specimen is exposed to view. The bones of one of the hind-feet are detached from the trunk and imbedded above the anterior part of the skeleton; and the extremity of the tail is dislocated and somewhat broken. Portions of the dermal scaly covering are preserved. I will now point out the most important osteological peculiarities observable in this specimen; reminding the visitor that the upper part of the skull is the lowermost in its present position, and referring to M. Cuvier's work for those details which the scientific observer will require.

1

The form of the skull resembles that of the Gavial, but the bones of which it is composed present manifest differences from those of the recent species; the symphysis of the lower jaw is relatively shorter. The teeth are 106 in number, and placed in distinct sockets, as in the Crocodiles; they are more acuminated and curved, and stand out more prominently than in the Gavial, and their surface is finely striated longitudinally. There are twenty-five or six on each side the lower jaw, and they are alternately longer and smaller, counting from the fourth tooth, so that the fifth and seventh are only half the height of the sixth and eighth, and so on. In the upper jaw the teeth are of equal size, except the first two, which are small, and the third tooth, which is very large. The palatine surface of the upper jaw is exposed. The occipital condyle, and the facet of the tympanic bone to articulate with the lower jaw, are distinctly shown.

There are seventy-nine biconcave vertebræ ; the articular surfaces of their bodies are but slightly depressed; the cervicals have lost their transverse processes. The caudal vertebræ exceed by ten the number in the tail of any known crocodile. There are twenty-three ribs which are displaced, but are more or less entire. There are some of the bones of the pectoral and pelvic arches, namely, one of the coracoids, an ilium, ischium, and fragments of the sternum. The left hind foot is in its

1 The uppermost part of the specimen as seen in the Case.

place, but detached, and the bones dislocated; those of the right foot are in natural connection, but altogether separated from the trunk, and lying above the lower jaw, according to the present position of the fossil in Case B. The length of the femur is double that of the tibia. The number of fingers and toes accord with those of the Crocodile. There are

many dermal scutes scattered among the bones; the median dorsal ones are carinated; in one part there are twenty-six in natural apposition; the original must have been covered by a strong flexible scaly integument. In this small reptile, and in the remains of the large Swanage Goniopholis, we have instructive examples of the modification of crocodilian structure which so largely prevailed during the Wealden and Oolitic ages.

Teleosaurus Chapmanni.-Wall-case B.'- "The head and other parts of the skeleton of a Gavial from the Lias at Whitby, which, though correctly determined by its discoverer, Capt. W. Chapman, and also by Wooller, (Philosophical Transactions for 1758,) was subsequently mistaken for an Ichthyosaurus."

The fine specimen in the lower compartment of Case B, appears to be the one above specified. It consists of a slab of Lias limestone, on which are imbedded the cranium and mandibles attached to a part of the vertebral column, with many ribs and dermal bones. The skull and jaws are between three and four feet in length. The head is retroverted, so that the under surface of the lower jaw is exposed.

In the upper part of the same Case there is a specimen of

1 The following is the arrangement of the Teleosauri in this part of Wall-case B:

Uppermost.-Teleosaurus Chapmanni, 9 feet long.

Shelf. Several portions of crania and jaws. Vertebræ and dermal bones
of Teleosauri.

Teleosaurus Chapmanni.-(Philos. Trans. for 1758.)

Cast of Teleosaurus
cadomensis,

On the bottom.-Portions of gigantic jaws with teeth of Gavials from the
Eocene strata of the Sewalik Hills. Presented by
G. H. Smith, Esq.

2 "Synopsis of the British Museum;" p. 89.

this species of Teleosaurus, nine feet in length; the cranium is very fine, the vertebral column is arched, and almost perfect to the extremity of the tail; a row of dermal scutes extends along the dorsal region. Of the fore-limbs the

humerus only remains; but of the hinder right limb, the femur, bones of the leg, and many of the feet, are preserved. This fossil is probably from the same locality as the one above described. The lias of the Yorkshire coast is celebrated for the abundance and variety of the remains of fossil plants, and of reptiles and other animals, that may be easily obtained by a little assiduity and perseverance.

There is also on the same ledge part of the cranium and jaws with teeth of another individual from Saltwich near Whitby; presented to the Museum in 1834; it is figured in Dr. Buckland's Bridgewater Essay, pl. XXV.

On the top of this Wall-case there is a much larger and finer specimen of the Teleosaurus than either of the above. The skeleton from the point of the muzzle to the end of the tail is preserved; most of the bones of the extremities are exposed, and numerous remains of the osseous dermal scutes. In the Case above the Teleosaurus priscus, there is an example of this species about seven or eight feet in length.

Dr. Buckland figures a specimen (pl. XXV.) which he describes as one of the finest of fossil Teleosauri yet discovered. "Its entire length, if perfect, would be about eighteen feet, the breadth of the head one foot; the snout is long and slender as in the Gavial; the teeth, 140 in number, are all small, slender, and placed in nearly a straight line. Some of the unguical phalanges that are preserved on the hind feet of this animal, show that the toes were terminated by long and sharp claws, adapted for motion on land."1

The anatomical structure and natural affinities of this species of saurian are fully considered by Professor Owen, in the Reports on British Fossil Reptiles, to which I must refer the scientific inquirer; it will suffice for our present purpose to state the leading characters which distinguish it.2

1 Bridgewater Essay, p. 253.

2 British Association Report for 1841; pp. 72-80.

The cranium is broad posteriorly and square-shaped; it begins to contract anterior to the orbits, and gradually extends into a narrow depressed snout. The orbits are subcircular, and are directed upwards and outwards. The columella or ossicle of the ear is cylindrical, and relatively larger than in any known reptile. The entire length of the cranium and mandibles in some individuals was from four to five feet. The teeth are slender and sharp pointed, and amount to 140.

The spine is composed of sixty-four biconcave vertebræ ; viz.: seven cervical, sixteen dorsal, three lumbar, two sacral, and thirty-six caudal. The largest vertebræ are three inches in length. The ribs possess the usual crocodilian character; the number of dorsal ribs exceeds that of any existing crocodilian, amounting to sixteen pairs. The scapula and coracoids correspond with those of the Crocodile, but are smaller. The humerus and bones of the fore-arm are much shorter than in the Crocodile. The femur (15 inches long) is of the usual double-curved crocodilian form. The tibia and fibula (eight inches long), resemble those of the Teleosaurus priscus (ante, p. 178) in their relative shortness as compared with the femur. All the long bones, and even the metatarsals, are stated to have distinct medullary cavities.

The dermal scutes are arranged as in the existing gavials, both in longitudinal and transverse series: the pits on the external surface are nearly circular, and do not present the irregular forms observable in the scales of the Swanage Crocodile, (ante, p. 173.) The posterior margin of one scute covers the base of the succeeding one, and they overlap each other laterally; but there are no lateral points or processes as in the Goniopholis. The largest scutes are about 3 inches square.

TELEOSAURUS CADOMENSIS.-(On the right of Teleosaurus Chapmanni.)-This is a cast of the cranium and part of the vertebral column of a Teleosaurus, from the Oolite of Caen, in which locality remains of this species are common. This reptile was described by M. Cuvier as "Gavial de Caen," in "Oss. Foss." tome v. p. 127. It has 180 teeth; its beak, or mandible, is longer than in Teleosaurus priscus ; the dermal scutes are rectangular, and thin at the margin; there are fifteen or sixteen transverse rows between the