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from their operation, we infer the perfection of the wisdom by which all this mechanism was designed, and the immensity of the power by which it has ever been upheld.

Cuvier asserts of the Mosasaurus that before he had seen a single vertebra, or a bone of any of its extremities, he was enabled to announce the character of the entire skeleton, from the examination of the jaws and teeth alone, and even from a single tooth. The power of doing this results from those magnificent laws of co-existence, which form the basis of the science of comparative anatomy, and which give the highest interest to its discoveries.

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AMONG the most remarkable disclosures made by the researches of Geology, we may rank the flying reptiles, which have been ranged by Cuvier under the genus Pterodactyle; a genus presenting more singular combinations of form, than we find in any other creatures yet discovered amid the ruins of the ancient earth.†

The structure of these animals is so exceedingly anomalous, that the first discovered Pterodactyle (Pl. 21) was considered by one naturalist to be a bird, by another as a species of bat, and by a third as a flying reptile.

This extraordinary discordance of opinion respecting a creature whose skeleton was almost entire, arose from the

See Pl. 1, Figs. 42, 43, and Plates 21, 22.

† Pterodactyles have hitherto been found chiefly in the quarries of lithographic limestone of the jura formation at Aichstadt and Solenhofen; a stone abounding in marine remains, and also containing Libellulæ, and other insects. They have also been discovered in the lias of Lyme Regis, and in oolitic slate of Stonesfield.

presence of characters apparently belonging to each of the three classes to which it was referred. The form of its head, and length of neck, resembling that of birds, its wings approaching to the proportion and form of those of bats, and the body and tail approximating to those of ordinary Mammalia. These characters, connected with a small skull, as is usual among reptiles, and a beak furnished with not less than sixty pointed teeth, presented a combination of apparent anomalies which it was reserved for the genius of Cuvier to reconcile. In his hands, this apparently monstrous production of the ancient world, has been converted into one of the most beautiful examples yet afforded by comparative anatomy, of the harmony that pervades all nature, in the adaptation of the same parts of the animal frame, to infinitely varied conditions of existence.

In the case of the Pterodactyle we have an extinct genus of the Order Saurians, in the class of Reptiles, (a class that now moves only on the land or in the water,) adapted by a peculiarity of structure to fly in the air. It will be interesting to see how the anterior extremity, which in the fore-leg of the modern Lizard and Crocodiles is an organ of locomotion on land, became converted into a membraniferous wing; and how far the other parts of the body are modified so as to fit the entire animal machine for the functions of flight. The details of this inquiry will afford such striking examples of numerical agreement in the component bones of every limb, with those in the corresponding limbs of living Lizards, and are at the same time so illustrative of contrivances for the adjustment of the same organ to effect different ends, that I shall select for examination a few points, from the long and beautiful analysis which Cuvier has given of the structure of this animal.

The Pterodactyles are ranked by Cuvier among the most extraordinary of all the extinct animals that have come under his consideration; and such as, if we saw them restored to life, would appear most strange, and most

unlike to any thing that exists in the present world.-"Ce sont incontestablement de tous les êtres dont ce livre nous révele l'ancienne existence, les plus extraordinaires, et ceux qui, si on les voyat vivans, paroîtroient les plus étrangers à toute la nature actuelle." (Cuv. Oss. Foss. Vol. V. Pt. 11, p. 379.

We are already acquainted with eight species of this genus, varying from the size of a Snipe to that of a Cormo

rant.*

In external form, these animals somewhat resemble our modern Bats and Vampires: most of them had the nose elongated, like the snout of a Crocodile, and armed with conical teeth. Their eyes were of enormous size, apparently enabling them to fly by night. From their wings projected fingers, terminated by long hooks, like the curved claw on the thumb of the Bat. These must have formed a powerful paw, wherewith the animal was enabled to creep or climb, or suspend itself from trees.

It is probable also that the Pterodactyles had the power of swimming which is so common in reptiles, and which

* In Pl. 21, I have given an engraving of the Pterodactylus longirostris, which was first published by Collini, and formed the basis on which this genus was established.

At Pl. 22, O. is engraved the smallest known species, P. Breviostris from Solenhofen, described by Professor Soemmering.

A figure and description of a third species, P. macronyx, from the lias at Lyme Regis, have been published by myself, (Geol. Trans. Lond. second series, Vol. 3, Pt. 1.) This species was about the size of a Raven, and its wings, when expanded, must have been about four feet from tip to tip. A fourth species, P. crassirostris, has been described by Professor Goldfuss. In Pl. 22, N. I have given a reduced copy of his plate of the specimen; and in Pl. 22, A. a copy of his restoration of the entire animal. Count "Munster has described another species, P. medius, Cuvier describes some bones of a species, P. grandis, four times as large as P. longirostris, which latter was about the size of a Woodcock. Professor Goldfuss has described a seventh species from Solenhofen, P. Munsteri; and has proposed the name P. Buck landi, for the eighth undescribed species found at Stonesfield.

is now possessed by the Pteropus Pselaphon, or Vampire Bat of the island of Bonin. (See Zool. Journ. No. 16, p. 458.) "Thus, like Milton's fiend, all qualified for all services and all elements, the creature was a fit companion for the kindred reptiles that swarmed in the seas, or crawled on the shores of a turbulent planet.

The Fiend,

O'er bog, or steep, through strait, rough, dense, or rare,
With head, hands, wings, or feet, pursues his way,
And swims, or sinks, or wades, or creeps, or flies.'

Paradise Lost, Book II. line 947.

With flocks of such like creatures flying in the air, and shoals of no less monstrous Ichthyosauri and Plesiosauri swarming in the ocean, and gigantic Crocodiles, and Tortoises crawling on the shores of the primeval lakes and rivers, air, sea, and land must have been strangely tenanted in these early periods of our infant world.”*

As the most obvious feature of these fossil reptiles is the presence of organs of flight, it is natural to look for the peculiarities of the Bird or Bat, in the structure of their component bones. All attempts, however, to identify them with Birds are stopped at once by the fact of their having teeth in the beak, resembling those of reptiles: the form of a single bone, the os quadratum, enabled Cuvier to pronounce at once that the creature was a Lizard: but a Lizard possessing wings exists not in the present creation, and is to be found only among the Dragons of romance and heraldry;† while a moment's comparison of the head

* Geol. Trans. Lond. N. S. Vol. III. part. 1.

† One diminutive living species of Lizard, (the Draco volans, see Pl. 22, L.) differs from all other Saurians, in having an appearance of im perfect wings, produced by a membranous expansion of the skin over the false ribs which project almost horizontally from the back; the membrane expanded by these false ribs, acts like a parachute to support the animal in leaping from tree to tree, but has no power to beat the

and teeth with those of Bats (Pl. 21, and Pl. 22, M.) shows that the fossil animals in question cannot be referred to that family of flying Mammalia.

The vertebræ of the neck are much elongated, and are six or seven only in number, whereas they vary from nine to twenty-three in birds.* In birds the vertebræ of the back also vary from seven to eleven, whilst in the Pterodactyles there are nearly twenty; the ribs of the Pterodactyles are thin and thread-shaped, like those of Lizards, those of birds are flat and broad, with a still broader recurrent apophysis, peculiar to them. In the foot of birds, the metatarsal bones are consolidated into one in the Pterodactyles all the metatarsal bones are distinct; the bones of the pelvis also differ widely from those of a bird, and resemble those of a Lizard; all these points of agreement, with the type of Lizards, and of difference from the character of birds, leave no doubt as to the place in which the Pterodactyles must be ranged, among the Lizards, notwithstanding the approximation which the possession of wings seems to give them to Birds or Bats.

The number and proportions of the bones in the fingers and toes in the Pterodactyle, require to be examined in some

air, or become an instrument of true flight, like the arm or wing of Birds and Bats; the arm or fore leg of the Draco volans differs not from that of common Lizards.

* In one species of Pterodactyle, viz., the P. macronyx, Geol. Trans. N. s. V. iii. pl. 27, p. page 220, from the lias at Lyme Regis, there is an unusual provision for giving support and movement to a large head at the extremity of a long neck, by the occurrence of bony tendons running parallel to the cervical vertebræ, like the tendons that pass along the back of the Pigmy Musk, (Moschus pigmæus,) and of many birds. This provision does not occur in any modern Lizards, whose necks are short, and require no such aid to support the head. In the compensation which these tendons afforded for the weakness arising from the elongation of the neck, we have an example of the same mechanism in an extinct order of the most ancient reptiles, which is still applied to strengthen other parts of the vertebral column, in a few existing species of mammalia and birds.

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