The Chelydes.- 



-REPTILES. EiVER Tortoises. 



73 



aud with the exception of the genus Chelodina we 

 always observe two small barbels under the skin. The 

 limbs are not much provided with scales, and the toes, 

 which are deeply webbed, have in all but the geims 

 Chelodina the fifth toe of the hind feet destitute of a 

 claw. They are natives of ponds and rivers in warm 

 climates ; eat flesh, feeding ouly in the water, and 

 swimming with their whole shell under the surface. 



About thirty-four species have been described, which 

 are nearly equally distributed in Africa, America, and 

 A'listralia. 



Forming a sort of passage from the Terrapens to the 

 Chelydes, we first come to notice the genus Sterno- 

 TH^RUS. In it the sternum or breastplate is mov- 

 able, as well as in the Box tortoises ; but unlike that 

 of the genus Cistudo, which has the sternum divided 

 by two cross sutures, the central lobe being attached 

 to the tliorax by a bony suture, in this genus the 

 bieastplate is broad, and it is the front lobe only which 

 is movable. It is rounded in front, and furnished on 

 each side of its hinder edge with an internal bony pro- 

 cess. The species are all n;itives of Africa. 



THE NATAL STERNOTHEEE [Sternothwriiscaslaneus) 

 has been described and figured by Sir Andrew Smith 

 in his " Illustrations of the Zoology of South Africa." 

 " The first specimens," he says, " of this tortoise were 

 discovered in rivers to the north of 25° south latitude ; 

 aud in situations only where the water was very deep. 

 They were usually observed during the heat of the day 

 lying upon rocks which projected above the surface of 

 the water, and were so vigilant that it was almost im- 

 possible to approach them within a moderate distance 

 before they vanished. Many of them were struck by 

 musket balls, yet no wounds which were thus inflicted 

 ever appeared to impede their movements. At last, 

 by means of hooks baited with flesh, we succeeded in 

 obtaining a few specimens, though against such means 

 they were also guarded ; for even where individuals 

 e.\isted in abundance, perhaps not one could be secured 

 by four or five fishermen, after spending many hours 

 in the pursuit." This is the only species of the family 

 that has the breastplate movable. In all the others 

 it is solidly fixed. 



Amongst the species which are natives of America, 

 one is very reraarkalile : — 



THE MATAMATA OR FIMBRIATED TORTOISE 

 [Chelys matamata) is an animal of a very singular 

 and unpleasing appearance, and is distinguished from 

 all others by the extraordinary projection of its body 

 out of the shell, so that when in a state of repose, or 

 even when suddenly wounded, it can only retract part 

 of it within the shell. The neck is remarkably thick 

 and flat, is seven and a half inches long and four and 

 a half broad, and is fringed on each side and under- 

 neath with a number of membranaceous appendages, 

 disposed longitudinally, and alternately larger and 

 smaller. The head is large and flat, rounded in front, 

 and edged on the sides with a number of warty, mem- 

 branaceous appendages similar to those of tlie neck. 

 The muzzle is cylindrical, and is elongated in fonn of 

 a tubular proboscis ten inches long, and pierced by the 

 nostrils at the tip, where they are separated by a car- 

 tilaginous division. The mouth is large and wide, 

 " Vol. II. 



and the jaws are simple and covered with soft lips. 

 The shell is ovate, oblong, and the shields with whicli 

 it is covered are elevated, acute, and form three keels. 

 The breastplate is narrow, broader and rounded iji 

 front, and narrower and bifid behind The colour of 

 the carapace is a uniform deep-brown above, a httle 

 paler below. The total length of the animal is two 

 feet three inches ; the shell being one foot three inches, 

 and the neck seven inches long. It is a native of South 

 America, and is known to the aboriginal inhabitants of 

 the district of Cayenne, in which it used to occur plen- 

 tifully, by the name of Matanuita. Bruguiere was the 

 first that gave an accurate description of this curious 

 looking tortoise. According to him, it inhabits Guiana, 

 in some parts of which it is very common, but is now 

 become rare in the rivers of Cayenne, on account of its 

 being so much in request as a highly prized article of 

 food. It remains concealed during the day, and only 

 sahies forth at night to feed. Its food is said by this 

 author to consist of the herbs which grow upon the 

 borders of the rivers and ponds in which it lives ; but 

 this is denied by Martin, who aifirms it to be carnivor- 

 ous. " It inhabits," he says, " fresh-water ponds aud 

 rivers, and conceals itself under the leaves of aquatic 

 plants, with only the extremity of its nose, which is like 

 a small proboscis, above the surface; in this position it 

 awaits the approach of young birds, fishes, and small 

 aquatic animals, which it seizes as they pass near it. 

 It swims with rapidity, and darts eagerly on its prey." 

 About the latter end of last century, M. Gautier, 

 governor of the Senegal Company of France, had 

 several specimens collected by himself in Cayenne, one 

 of w-hich he kept alive in Paris for several months. 

 During its captivity it was fed upon bread and herbs, 

 which it ale readily, and before it died it laid five or 

 six eggs. One of these, which was kept in a drawer, 

 very unexpectedly excluded a young one. 



Several species of the family of Chelydes are, as we 

 have mentioned above, natives of Australia, but we 

 have not space for these. 



SOFT TURTLES or EIVER TORTOISES 

 ( Trionycidai). 



The species of this group of tortoises are compara- 

 tively few in number, but they form a very natural 

 family. Although inhabitants of the fresh water, 

 they differ from the preceding families considerably 

 in their conformation and structure, as well as in 

 their habits. Like the Marine turtles, to be hereafter 

 noticed, these River tortoises are compelled to live 

 constantly in the water, but, unlike the Pond or Marsh 

 tortoises, which we have already considered, and which 

 sojourn in still water, as ponds, marshes, and slow run- 

 ning muddy streams, these creatures inhabit large and 

 rapid flowing rivers. They swim well and with great 

 rapidity, and to answer this purpose their toes are 

 deeply webbed to the very claws with broad flexible 

 membranes. Their feet in fiict, both fore and hinder, 

 are changed into true fins, which are no longer fitted 

 for progi'cssion on land, but are admirably adapted for 

 propelling tliem through the water. Their neck is 

 generally very long and protractile ; the head is narrow 



