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Show 14 REPTILIA. reaching to the spine, and which appear to be produced by the ossification of the tendinous inscriptions of the recti muscles. Their lungs do not dip into the abdomen like those of other rep· tiles, and some fleshy fibres, adhering to that part of the peritoneum which covers the liver, give them the appearance of a diaphragm, which, in conjunction with the division of their heart into three chambers, where the blood from the lungs does not mingle so per· fectly with that from the body as in other reptiles, appproximates them somewhat nearer to the hot-blooded quadrupeds. The tympanum and pterygoid apophyses are fixed to the cranium as in the Tortoises. Their eggs are as large and hard as those of a Goose; and Crocodiles are considered, of all animals, those which present the greatest difference in size. The females keep careful watch over their eggs, and tenderly protect their young for some months. They inhabit fresh water, are extremely ferocious and car· nivorous, cannot swallow under water, but drown their prey, and place it in some submerged crevice of a rock, where they allow it to putrefy before they eat it.( 1) The species, which are more numerous than they were thought to be previous to my observations, are referable to three distinct sub· genera. GAviAL, Cuv. The muzzle slender and very long; the teeth pearly equal; the fourth ones below passing, when the jaws are closed, into notches, and not into holes, in the upper one; the external edges of the hind feet are notched, and the feet themselves palma ted to the very ends of the toes; two large holes in the bones of the cranium behind the eyes may be felt through the skin. They have as yet been found in only the eastern continent. The most common is, Lac. gangetica, Gm.; Gavial du Gange; Faujas, Hist. de Ia Mont.~ de St Pierre, pl. xlvi; Lacep. I, xv. A species which attains a great size, and which, besides the length of its muzzle, is remarkable for a stout cartilaginous prominence which encir· cles its nostrils, and then inclines backwards.(2) ( 1) Crocodiles differ so much from Lizards that several authors have recently thought it proper to form them into a separate order. They are the LoRIC.&TJ., Merrem and Fitzinger; the EMYDOSA.URIA, Blainv. (2) This prominence is the foundation of JElian's remark (Hist. an. LXfl, c. 41), that the Ganges produces Crocodiles which have a horn on the end of the muzzle. See its figure and description by Geoff. St Hillaire, Mem. du Mus. XII, P· 97. . Add, the Petit Gavial ( Croc. te:nuirostris, Cuv. ), Faujas, loc. cit. pl. xi viii, should 1t prove to be a distinct species. N.B. The calcareous schist of Bavaria has produced a small fossil Gavial of a SA URI A. 15 CROCODILES,( 1) properly SO called. Have an oblong and depressed muzzle, unequal teeth, the fourth ones below passing into notches, and not into holes of the upper jaw, and all the remaining characters of the preceding subgenus. They are found in both continents. Lac. crocodilus~ L.; Crocodile du Nil., Geoffr. Descr. de l'Egypte, Rep. II, 1; Ann. Mus. X, iii, I; Cuv. lb. X, pl. 1, f. 5 and 11, f. 7, and Oss. foss. V, part 2, same plate and figure (The Crocodile of the Nile), so celebrated among the ancients, has six rows of square and nearly equal plates along the whole length of the back.(2) peculiar species, described by Sremmering in the Mem. of the A cad. of Munich, of 1814. I have described the crania and other parts of fossil Crocodiles allied to the Gavials found at Caen, Ilonfleur and other places, and marked those points in which the osteology of their cranium differs from th!tt of the Gavial now in exist· ence. See Oss. foss. V, part 2. Similar observations have also been made in England by M. Conybeare. In consequence of these differences, which all relate to the hind part of the palate, M. Geoffroy has thought proper to form two genera ofthese lost animals, which he calls TaELEOsA.unus and STENEOSA.URus, notwithstanding which, he appears to think they may be the stock of the present Gavials, and that the said differences may have resulted from atmospheric changes. Mem. du Mus., XII. · (1) Kpox.oJ'u11.0~, wMch fears the shore, a name given by the Greeks to a common Lizard of their country; they afterwards, in their travels through Egypt, applied it to the Crocodile from the mutual resemblance. Herodot. Lib. II. Merrem has changed the name of this subgenus to that of CnA.M:PSEs, which, according to Herodotus, was the Egyptian name of this animal. . (~) From the Senegal to the Ganges, and beyond it, we find Crocodiles very stmtlar to the common one, some of which have a rather longer and narrower muzzle, and others, a difference in the plates or scales which cover the top of their neck; but it is very difficult to arrange them as distinct species, ou account of their intermediate gradations. The small insulated scales which form a transverse row immediately behind the cranium, vary from two, to four and six; the approximated scales which compose the shield of the neck are generally six in number, but sometimes there is a smallet• one at but little distance from each of the anterior angles of this shield, and at others it is contiguous to ~t, in which case it (the shield) consists of eight plates or scales. M. Geoffroy calls those which have a longer and narrower muzzle, Oroc. sucltus; those whose row of scales behind the cranium consists of six pieces, Croc. marginatus., among which some h~ve six plates in the shield, and others eight; Oroc. lacunosus, an individual speet~ en which only presented two scales behind the cranium, and six plates in the shteld; and, finally, another specimen whose chat•acters are referable to some proportions of the head) Oroc. complanatus. These various Crocodiles also differ in some of the details of the form of the muz~le, and in the lateral scales of the back, but as regards this, and the muzzle parttcularly, the varieties are still more numerous, and M. Geoffroy acknowledges that nothing is more fugitive than the form& of OrocodilC8. This is so much the case, |
