expanse, have a remarkably small skull, with beaks furnished, in some species, with upwards of sixty sharp-pointed teeth, and generally very long. The teeth are simple, of a conical form, recurved, and implanted in distinct sockets, with considerable intervals between them. The orbits are very large, and the neck elongated. The sternum and pectoral arch are

constructed as in reptiles. The peculiar organization of the fore-foot, and which entirely differs from that of any other reptile, whether recent or fossil, consists in the great extension of the fore-finger, which is composed of five bones, and exceeds in length the entire spinal column; the other digits are of the ordinary relative proportions, and armed with claws.' Impressions of the delicate membranous expansion, or wing, which this finger was designed to support, are occasionally

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1 There are excellent figures of Pterodactyles in Dr. Buckland's Bridgewater Essay," Pl. XXI. and Pl. XXII.

observed on the stone surrounding the phalangeal bones (as in Lign. 42).

The nature of the original animal was traced by Baron Cuvier with his accustomed terseness and perspicuity; and later discoveries, though enlarging our knowledge of this remarkable order of reptiles, and presenting us with far more colossal forms than could have been rationally predicated, have added nothing of importance to the original sketch by the master-hand.

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"The Pterodactyle," observes M. Cuvier, was an animal which in its osteology, from the teeth to the extremities of the claws, and from its skull to the end of the tail, presented the classic characters of the saurians. We therefore cannot doubt that it had the same modifications in the integuments and soft parts; their dermal covering, circulation, organs of generation, &c. At the same time, it was provided with large membranous wings, and its powers of flight must have far exceeded those of the Draco volans, the only existing reptile that can traverse the air, and probably equalled those of the Bat. It doubtless could flit and soar on the wing as long as the strength of its muscles permitted, and suspend itself to trees or rocks by its short unguiculated toes. Its position, when in repose, would probably be like that of birds, on its hind legs, with the neck straightened and curved back, to preserve its equilibrium."

PTERODACTYLUS MACRONYX.-Wall-case A-B.1-These unique remains of a species of Pterodactyle, which, when living, was about the size of a raven, were discovered in 1828, by the late Mary Anning, the well-known intelligent collector of the fossils from the liassic deposits that form the cliffs along the coast of Dorsetshire, near Lyme Regis. I have not heard that any other relics of this species have been met with.

This specimen was figured and described by Dr. Buckland in "Geol. Trans." vol. iii. Pl. XXVII. with the specific name macronyx, suggested by the great length of the claws.2 It consists of a few fragments of the cervical and dorsal vertebræ, and three caudals; the scapula and coracoids; and the bones

1 Figured and described by Dr. Buckland in "Geol. Trans." vol. iii. new series, p. 217.

2 The specimen was purchased of Miss Anning by the Trustees of the British Museum.

of the arms, and fingers, more or less displaced. These several parts are enumerated by Dr. Buckland as follows :

"One cervical vertebra, of an inch in length; near this bone are small cylindrical ossified tendons, resembling the tendons which run parallel to the caudal vertebræ of rats.

Dorsal and lumbar vertebræ, in a fragmentary state.

Three caudal vertebræ.

Two scapulæ, or omoplates, long and narrow, as in crocodiles.

Two coracoids, large, as in birds, for the support of the wings in flight. Sternum, broken and indistinct.

Humeri. The right humerus and scapula are much displaced; the left humerus, and other bones of the left wing, are nearly in their natural juxta-position.

Fore-arm there are no traces of an ulna.

Carpus: in the left, four bones are well preserved, three in contact with the radius, the fourth with the largest metacarpal, The right carpal bones are all dispersed.

Metacarpals; first, second, and third of the right hand, and also of the left; and the fourth of each hand supporting the respective wingfingers.

Three fingers of the left hand, terminating in long claws; there are two phalanges in the first, three in the second, and four in the third finger, as in crocodiles.

All the bones of the first and third fingers of the right hand.

First bone of the fourth or wing-finger; there is no vestige of a fifth finger.

Pelvis: the three bones of the right side, viz., the ilium, ischium, and pubis, are very distinct.

The two femora; the right one displaced.

The tibiæ; the left one compressed: there are no traces of fibulæ.
Tarsus, but faintly indicated.

Metatarsus; four of the left foot distinct and undisturbed, their under aspect being exposed.

Phalanges of the left toes, the claws wanting.

Toes of the right foot, much displaced; one claw only remains.

The length of the foot, and of the tibia and femur, shows that the animal must have stood firmly on the ground, on which, probably, with its wings folded, it moved after the manner of birds. It could, perhaps, also perch on trees, and cling to their branches by means of its feet and toes, like birds and lizards."1

WEALDEN PTERODACTYLES.- -Wall-case A-B.-In the Wealden deposits, and likewise in the Stonefield calcareous slate,

1 Dr. Buckland. "Geol. Trans." p. 222. The above details are inserted for the use of the scientific visitor who may be desirous of examining this unique specimen.

fragments of bones of such tenuity as to indicate that they belonged to animals capable of progression through the air, are not uncommon. Their occurrence in the Wealden deposits was first noticed in my earliest work, "On the Geology of Sussex;" but, although thirty years have since elapsed, I have not seen a specimen with articular extremities so perfect as to demonstrate with certainty whether it belonged to a bird or to a flying reptile. In the Case before us there are a few portions of long bones which are probably metacarpals and phalangeals of pterodactyles; and in some of the closed cabinets there are a few specimens more illustrative. There is one bone, especially, which was formerly supposed to be the tarso-metatarsal of a bird, but has since been ascertained to be a humerus, and, probably, of a Pterodactyle; although there are certain points in which it unquestionably differs from the arm-bone of any flying reptile hitherto observed.

In the absence of obvious distinctive osteological characters, it was hoped that an investigation of the intimate structure of these enigmatical remains would throw light on the subject, and that the microscopical examination of the most characteristic bones by Mr. Quekett and Mr. Bowerbank might afford a solution of the problem.

In a paper communicated to the Geological Society by Mr. Bowerbank, that able observer affirms that there is a recognisable difference in the form and proportion of the bone-cells in birds and reptiles, which he believes to be constant, and by which the smallest fragment of bone may with great probability be referred to its proper class.

In birds, under a power of 500 linears, Mr. Bowerbank found the cells to have a breadth in proportion to their length, as one to four or five; while in reptiles the length exceeds the breadth ten or twelve times. For example, in the albatross the width of the cell is one-fourth the length, and in the crocodile one-twelfth.1 Applying this test to the bones supposed by Professor Owen to be those of a bird allied

1 Professor Owen remarks," Such a statement as that these cells in Birds have a breadth, in proportion to their length, of from one to four or five, while in Reptiles the length exceeds the breadth by ten or twelve times, only betrays the limited experience of the assertor;" and he quotes" Mantell's Wonders of Geology," vol. i. p. 441. Now as the statement in my work was submitted to Mr. Bowerbank's revision before it was printed, the amiable Professor has missed his mark, and hit

to the albatross,' Mr. Bowerbank pronounced them to belong to a Pterodactyle; probably to the colossal species (named by him P. giganteus), of which he had obtained jaws with teeth, and other remains, from the same chalk quarry; a conclusion which has since been satisfactorily established.

On the other hand, certain bones from the Wealden and Oolite are regarded both by Mr. Quekett, and Mr. Bowerbank, as exhibiting unequivocally a structure peculiar to birds.

With regard to the value of such evidence, I would venture to express my opinion, that although in the entire absence of more obvious and certain diagnostic characters, it would be unsafe to admit the relative proportions of the bone-cells as conclusive proof, it is not unreasonable to infer that the intimate structure of the solid parts of the skeleton may have relation to the peculiar organisation of a class, and that the microscopic test, if applied with due caution, will prove an important auxiliary in the interpretation of the true nature of the fossil bones of unknown animals.

Some of these presumed birds' bones are so extremely thin

the distinguished Honorary Secretary of the Palæontographical Society, to whose indulgent consideration I therefore leave him.*

1 These bones from the Kentish Chalk are described in Professor Owen's" BRITISH MAMMALS AND BIRDS," under the name of " CIMOLIORNIS DIOMEDEUS. Long-winged Bird of the Chalk," " Bird allied to the Albatross," (Diomedea). In the late Mr. Dixon's work, edited by Professor Owen, and published last year (1850), he again figures the specimen (though not a Sussex Fossil), and affirms, " I have yet obtained no evidence which shakes my original conclusion, that the bone is part of the shaft of a humerus of a longipennate bird, like the Albatross." (Dixon, p. 402.) And after commenting on Mr. Bowerbank's observations, he remarks, "When such obvious ornithic characters as these, and especially those of the trochlear end of the bone, determine their nature," &c. And yet Professor Owen accuses me of "misrepresenting him," and of being guilty of an "unamiable exaggeration "+ of his mistake, because, in a popular work, "The Wonders of Geology," I stated that he had regarded the bone as belonging to an extinct species of Albatross," using the word species in its general sense, as a sort, or kind. If I had written " a species of the genus Diomedea or Albatross," it might have borne the interpretation Professor Owen now affects to put upon it. The same unamiable expression was employed in my " Medals of Creation" (p. 804), published seven years ago, and then gave no offence !

*See Professor Owen's "Fossil Reptilia of the Cretaceous Formation," -Monographs of the Palæontographical Society, 1851, p. 83.

+ Ibid. p. 82-p. 83.