CHELONIA. 



C1IKI.ONIA. 



with the rapidity of an arrow. They bite sharp with their trenchant 

 beak, and do not let go till they hare taken the piece Mixed out ; no 

 that their bite U much dreaded, and the fiiihermen generally cut off 

 their head* as soon ai they have caught them. 



The male* appear to be fewer in nuniln-r than the females, or at 

 least they come lam frequently to the hanks of riven, where the 

 female* resort to deposit their eggs in hollows, which contain from 

 fifty to sixty. The number varies according to the age of the females, 

 which are less fruitful in proportion to their youth. The eggs are 

 spherical, their shell is solid, but membranous or slightly calcareous. 



dymiwpui, Dum. and Bihr. (Trimyx, Geoff; Atpidontcta, Wagler). 

 Carapace with a cartilaginous circumference, very large, flouting 

 behind, and deprived of bone externally ; sternum too narrow behind 

 to hide the limbs completely when the animal draws them up under 

 the carapace. Trinity* and Tettwio fti-os of authors. 



Q. pim/rrw. M. Lesueur states that towards the end of April, 

 or must frequently in Hay, the females of this species seek out on the 

 river banks sandy spots for the depo ut of their eggs ; steeps of ten or 

 fifteen feet elevation deter them not when they are choosing places 

 exposed to the sun. Their eggs are spherical, and their shell is more 

 fragile than that of the eggs of the species of Klodians living in the same 

 waters ; their eggs amount to from fifty to sixty. H. Lesueur counted 

 in the ovary twenty ready for laying, and a great quantity of others 

 of variable dimensions, from that <>f a pin's head to the much greater 

 volume which they attain when they are covered with their calcareous 

 coat The retreats of these tortoises are on rocks and on the trunks 

 of trees overthrown in the river. They may be taken with honk and 

 line baited with a little fish ; they are very voracious, and bite their 

 captors, so that the prudent cut off their heads. M. Lesueur was 

 often bitten by those he had: they dart out their heads like lightning. 

 The young begin to show themselves in July. The flesh of this 

 species is very delicate. 



Gymnoput ipinifrru*. 



0. mu/inw (Trionyx mtilievi, Lesueur, Lecoote, and Gray). 



O. jKgyptiarui (Trumyx jEgyptiaeiu, Gooff. ; T. JfUotitui, Gray). 

 This is supposed to be the 'EMM of Aristotle ('De Part Anim.,' 

 T. 9). 



O. Duvaucdit (Trionyx Gangetiau, Cuv. ; T. Jfurum. Gray) ; O. 

 orrllattu (Trionyx oceUaliu, Hardwick ; T. Hurum, the young, Gray) ; 

 '.. linrnltu (Trionyx jEffyj-tianu, var., Hunlw. ; T. Jndicut, ' 

 Q. Javanietu (Trionyx Jaraiticv*, Schweigg.) ; G. lubplanvt (Trionyx 

 nApltunu, Geoff.) ; G. Euphratic** (Trionyr Euphraticvt, Geoff). 



Oryptop*!, Dum. and Bibr. (Trionys, Wogl. ; Emyda, Gray). 

 Carapace with narrow cartilaginous borders supporting above the 

 neck and behind the thighs small bony pieces; sternum large, 

 forming in front a moveable door or lid which can hermetically close 

 the aperture of the osseous Iwx. The posterior part of the sternum 

 furnished right and left with a cartilaginous operculum, shutting the 

 apertures which give passage to the hind feet; there is a tliii.l 

 operculum besides to stop the opening whence the tail issues. 



C. yranona (Trionyx grmtomt, Schweigg.). It lives in fresh-water 

 lake*. The flesh is eaten. C. SenegoJauit. 



Family IV. Thalassians, Sea-Tortoises, or Turtles. (Chdoniada, 



Gray; CareHoidt, Kitzing. ; V/n/v A./..ric, Kitgen : 



Oiacopod Turlouri, Wagl.). 



This family is at once distinguished from all the others by the 

 comparatively depressed carapace and the long and broad paddles, 

 the anterior of which are very much prolonged when compared with 

 the posterior ones. Indeed their limbs are entirely so modified as to 

 become swimming organs. 



The Turtles hardly ever leave the sea excepting for the purpose of 

 laying their eggs ; but some accounts state that tliey will crawl up 

 the shores of desert islands in the night, and clamber up the edges of 

 isolated rocks far at sea, for the purpose of browsing on certain 

 favourite marine plants. They have been seen in smooth water as 

 far as 700 or 800 leagues from the land, floating motionless on the 

 surface of the sea as if they were dead, and it has been supposed that 

 they are then asleep. They dive well, and can remain beneath the 

 surface a long time, as might be expected from the extent and 

 volume of their arbitrary lungs, capable of retaining and furnishing a 

 sufficient quantity of air while they are submerged. 



Messrs. DumcYil and Bibron speak of the Potamians and Turtles aa 

 exceptions to the rest of the Chelmia, which, generally speaking, can 

 produce no other Rounds than hisses: we find however from Mr. 

 Darwin's account above given, that the Great Land-Tortoises, the 

 males at least, bellow loudly at the pairing season. The eric- .!' t!,.- 

 Potamiaus and of some Thalassians have been noticed by obf< 

 ;m.l especially those of the Coriaceous Turtle, or Sphargii, Individual* 

 of this last genus, when hampered in nets or grievously wounded, 

 have been heard to utter loud roars, from which they derive their 

 name (a<f>apayi(u, to roar, or cry loudly). 



The food of the Thalassians consists principally of marine plants : 

 but it appears that some of them, especially those which exhale a 

 musky odour, Chelonia Caotuina (Caotuma, Gray), for instance, feed 

 also on crustaceans and many species of mollusks, the cuttles especi- 

 ally. Their jaws are robust, like the beaks of birds of prey ; solidly 

 articulated and worked with highly developed muscles; and their 

 horny beak, hooked above and below, is trenchant on the edges, and 

 most frequently serrated, so as to assist in securing a slippery ptw. 



Whilst little is kn n with regard to the conduct of the two sexes 

 during the breeding season, those attending the deposit of the eggs are 

 better known. To reach the destined spot, the females have often to 

 traverse the sea for more than fifty leagues, and the males accompany 

 them to the sandy beaches of those desert islands selected for the 

 places of nidification. Arrived at the end of their voyage, they 

 timidly come forth from the sea after sunset ; and as it is necessary 

 to leave the eggs above high-water mark, they have often to drag 

 themselves to a considerable distance before they can hollow out 

 nests (about two feet in diameter) during the night, and there lay at 

 one sitting to the number of a hundred eggs. This laying is repeated 

 thrice, at intervals of two or three weeks. The eggs vary in si/.e, lint. 

 are spherical, like tennis-balls ; and when they are laid, their inventing 

 membrane is slightly flexible, although covered with n delicate cal- 

 careous layer. After slightly covering the nest with light sand, the 

 parent returns to the sea, leaving the eggs to the fostering influence 

 of a tropical sun. The eggs are said to be hatched from the 15th to 

 the 29th day ; and when the young turtles come out, their shel I 

 not yet formed, and they are white as if blanched. They in-tin. 

 make for the sea ; but on their road, and as they pause before entering 

 the water, the birds of prey that have lx en watching fur the moment 

 of their appearance hasten to devour them ; whilst those that have 

 escaped their terrestrial persecutors by getting into the sea, have 

 to encounter a host of voracious fishes and legions of ambushed 

 crocodiles. 



Those that escape attain, under favourable circumstances, enormous 

 dimensions. Individuals of the genus Spharytt have been known to 

 weigh from ISOOlbs. to Kino 11*.; and some whose carapace has 

 measured in its circumference more than 16 feet, and near 7 feet in 

 length, have weighed down more than from ISOOlbs. to 1900 Ibs. 

 Aged turtles often carry about with them on their carapace a little 

 world of parasites, such as Fltutree, Serpubt, Ita/ani, and Cornnnltr ; 

 whilst certain Annrlidn securely fix themselves at the origin or base 

 of the limbs, where the motion of the turtle cannot displace them. 



Though many of the other Chelonia are highly useful to man 

 cially as articles of food, none are of such great utility as tin I 

 sians. The advantages to be derived from them were not lost, n|.<m 

 the ancients; and though Mercury is said to have taken the first liint, 

 for the structure of a lyre from the dried carapace and tendons of a 

 tortoise (a (iymnbpta, probably), found by the god after an inundation 

 of the Nile, and which sounded when he struck 'the chorded shell,' 

 the benefits arising from the Thalassians are, if not so refined, of a 

 much more substantial and varied nature. The inhabitants of those 

 countries where the turtles grow to a large size do not merely derive 

 from them a supply of food, but they convert their carapaces into 

 boats, into huts, into drinking troughs for their domestic animals, and 

 baths for their children. The Chdonophagi of old, who inli 

 the shores of India and the Red Sea, converted the enormous shells 



