ORGANIC REMAINS. 



333 



formation of the secondary scries of strata, which may, with 

 propriety, be; denominated the age of lieptilei. Of these 

 gigantic races, then the dominant class of animals, not a single 

 species now inhabits our earth in a living- state. They seem to 

 have been the must formidable inhabitants both of land and 

 water. The living sauriaus, in comparison of the fossil kinds, 

 are but small animals. 



GENUS ICHTHYOSAURUS, (OR FISH LIZARD), 



Contains some of the most remarkable of these extinct rep- 

 tiles. They have received this name from the circumstance of 

 their vertebra; resembling those of fishes. These animals were 

 endowed with extraordinary structure, and combinations of 

 form, which are not now to be met with concentrated in one 

 individual. For example, we find in one species the snout 

 of a porpoise, the teeth of a crocodile, the head of a lizard, the 

 vertebrae of a fish, the sternum or collar-bone of an Ornitho- 

 rynchus, and the paddle- like fins of a whale, four in number. 

 The tail was long and powerful. There must have existed 

 seven or eight species, all pretty nearly alike. We have repre- 

 sented the common species, Ichthyosaurus communis, pi. 65, tiir. 

 49. The generic characters are, head long, wedge-shaped ; 

 orbits very large; nostrils placed near the anterior angle of the 

 eye ; teeth conical, very numerous, sometimes to the extent of 

 180, ranged in a continuous furrow ; jaws much elongated and 

 projecting into beaks, and composed of numerous thin plates ; 

 vertebral column consisting of upwards of 100 joints; ribs 

 slender, most of them bifurcated at top ; four feet or paddles, 

 shaped like those of whaler. 



GENUS PLESIOSAURUS. 



Head short, somewhat oblong, obtuse ; neck extremely long, 

 consisting of about thirty-three vertebrae; body elongated; tail 

 short; nostrils small, placed near the anterior angle of the eye; 

 teeth numerous, and lodge in small alveoli ; ribs composed of 

 two parts, the one vertebral and the other ventral, the ver- 

 tebral column consisting of about ninety joints. See flesiosau- 

 rui Dotoc/wtieirus, pi. 65, fig. 44. 



Perhaps there has been no animal created of a more extraor- 

 dinary form than this. In the length of neck it far exceeds 

 even the longest necked birds. It is in this species five times 

 the length of its head ; the trunk of the body four times the 

 length of the head ; and the tail three times ; while the head 

 itself is only a thirtieth part of the whole body. From the 

 whole physiology of the animal, Mr Conybeare says, that it was 

 aquatic is evident from the form of its paddles ; that it was 

 marine, is almost equally so, from the remains with which it is 

 universally associated ; that it may have occasionally visited 

 the shore, the resemblance of its extremities to those of the 

 turtle, may lead us to conjecture ; its motion, however, must 

 have been very awkward on land ; its long neck must have im- 

 peded its progress through the water, presenting a striking 

 contrast to the organization which so admirably fits the Ichthyo- 

 saurus to cut through the waves. May it not, therefore, be 

 concluded, (since, in addition to these circumstances, its respi- 

 ration must have required frequent access of air,) that it swam 

 upon, or near the surface ; arching back its long neck like the 

 swan, and occasionally darting it down at the fish which hap- 

 pened to float within its reach. It may, perhaps, have lurked 

 in shoal water along the coast, concealed among the seaweed, 

 and raising its nostrils to a level with the surface from a con- 

 siderable depth, may have found a secure retreat from the as- 

 saults of dangerous enemies ; while the length and flexibility 

 of its neck may have compensated for the want of strength in 

 its jaws, and its incapacity for swift motion through the water, 

 by the suddenness aud agility of the attack which they enabled 

 it to make on every animal fitted for its prey. 



GENUS MOSASAURUS. 



The form of the head and teeth are nearly allied to those of 

 the monitors. The teeth are fixed on the spheroid bone, and 

 situated in the roof of the mouth, acting as barbs to prevent 

 the escape of their prey; the vertebrae, 133 in number, are con- 

 cave in front, aud convex behind ; the tail flattened on each 

 side, but high and deep in a vertical position ; there are four 

 large paddles, like those of a whale. 



The Mosasaurui has evidently been entirely an aquatic ani- 

 mal. It has been known by the name of the great animal of 

 Maestricht, as it was found near that city, in the calcareous 

 free-stone, which forms the most recent deposit of the crota- 

 ceous formations. Remains of this animal have lately been 

 *bund by Mr Mantell, in the upper chalk, near Lewes, and by 

 Ur Morton, in the green sand of Virginia. The length of this 

 animal is about twenty-five feet; while none of the living 

 species, to which it is somewhat allied, exceed five inches. 



GENUS CROCODILUS. 



most remarkable of the genus is theCrocodilusPriscusof Sam- 

 mering, pi. 45, fig. 36. 1 his animal was discovered in a lime- 

 stone of a greyish white, which abounds iu ammonites, and 

 also furnishes enormous frize stones. It was in the celebrated 

 quarry of Solenhofien, in the valley of the AlUnuhl, a little 

 below Pappenheim, that this fossil was found. 



SUB-GENUS GROSAURUS. 



This is another sub-genus of large animals which seems to 

 form an intermediate link between the monitors and the croco- 

 diles. The remarkable animal, of which we have given a re- 

 presentation of its cranium, plate 65, fig. 21, and a single tooth, 

 fig. 22 ; three vertebrae, fig. 23, and a rib, fig. 24, was found 11 

 a district called Meulenhardt, ten feet deep, enveloped in a bed 

 of softish marl. 



GENUS PTERODACTYLE. 



The Pterpdactyle, or flying reptiles, are perhaps the most 

 singular animals which geological discovery has brought to 

 light. So remarkable are the forms, aud so incongruous the 

 combinations of structure, that the first discovered animal of 

 this genus was, by some naturalists, considered to be a bird, 

 by another a species of bat, and by a third a flying reptile. This 

 discrepancy of opinion arose from its possessing characters 

 which agreed with these various animals. In the form of its 

 head and length of its neck, it bears some analogy to birds : it 

 has wings allied in structure to those of bats, with a body and 

 tail approximating to those of the ordinary mammalia; and, 

 like that of reptiles, the skull is small. It is provided with a 

 beak, in which are placed sixty acute teeth. In this animal we 

 have the structure of a Saurian reptile, of which it forms an 

 extinct genus; with a conformation which adapts it for aerial ex- 

 cursions. In external form, these animals must have nearly 

 resembled the present vampire bats, so common in South Ame- 

 rica, but with much longer snouts, not unlike those of crocodiles, 

 and armed with conical teeth. Their eyes were of enormous 

 size, from which we may infer that they were nocturnal ani- 

 mals. Their wings had projecting hooked fingers, like those of 

 bats. These must have proved useful paws for the purpose of 

 prehension, and also for enabling them to creep and climb. It 

 seems probable that these animals possessed the power of swim- 

 ming, as well as all other reptiles, both extinct and recent. 



Eight species of this genus have been ascertained, varying in 

 size from a snipe to that of a cormorant. The smallest known 

 species is the Pterodactyle brevirostrii, from Solenhofen ; and 

 professor Buckland found the P. macronyx, in the lias at Lyme 

 Regis, which is about the size of a raven. 



GENUS MEGALOSAURUS. 



This genus was established by professor Buckland, and is a 

 lizard of great size. It appears to have been an enormous 

 reptile, measuring from forty to fifty feet in length, and in form 

 somewhat between the crocodile and the monitor. It was dis- 

 covered in the oolite slate of Stonefield, near Oxford; th 

 Erincipal place where these bones are yet found. Mr Mantell 

 as, however, detected some remains of this animal in the 

 Wealden fresh- water formations of Tilgate forest, from which 

 it may be inferred that it lived during the deposition of the en- 

 tire series of oolitic strata. A jaw, containing teeth and some 

 other bones, was found in the oolite at Besangon. 



GENUS IGUANADON. 



The teeth of this animal almost entirely agree in construe- 

 tion with those of the existing Iguana ; the construction of its 

 feet prove it to have been a terrestrial animal, and, like the 

 recent species, has had a horn of bone upon the nose. This 

 immense animal far outstrips all land species, whether extinct 

 or recent. Its length from the snout to the extremity of the 

 tail is seventy feet ; the length of the tail fifty-two and a half 

 feet; and the circumference of the body fourteen and a half 

 feet; whereas, the largest living species of Iguana does not 

 exceed five feet in length. Mr Mantell has calculated that the 

 thigh bone of the Iguanadon is twenty-five times larger than 

 that of the living species, far exceeding in bulk that of the 

 largest elephant ; the circumference in its smallest part being 

 twenty-two inches, its entire length must have been from 

 four to five feet. From the construction of its teeth, which are 

 much like those of the rhinoceros, it appears to have been a 

 strictly herbivorous animal. This enormous creature was found 

 by Mr Mantell in the fresh-water formation of Tilgate forest. 



ORDER III. CHELONIA. 



GENUS TESTUDO. 



The animals of this order are not met with in strata older 

 than the carboniferous scries. Cuvier mentions the shell of a 

 sea-turtle, which was found in the Muschelkalk at Luneville, 

 which measured eight feet in length. In the slate of the lower 

 cretaceous formation at Claris, another species was found; and 

 a third in the upper cretaceous free-tone at Maestricht. PI. 65, 

 fig. 8, is a representation of a fossil tortoise, found in the quar- 

 ries of Melsbroek, near Brussels. This was at first mistaken 

 by Cuvier for a marine species ; but more nttentive examina- 

 tion convinced him that it was a land animal. 



