nso 



CHELONIA. 



CHELONIA. 



990 



bones of the waist are flat and cut nearly square. In the first row ' 

 are two bones adhering to the ulna, and in the last row five smaller 

 ones, supporting the five bones of the metacarpus. There is besides 

 an intermediate bone under the first ulnar bone, and upon the second 

 and third of the last row. Cuvier observes that this would seem 

 to correspond with that dismembered trapezoidal bone which is 

 found in the monkeys. Lastly, there is a great semilunar bone out 

 of the rank, adhering to the external border of that which is above 



Skeleton anil Carapace of Cittudo Bulgaria, seen from below. 



;:: 







Skeleton and Carapace of Clielime Coftuana, seen from below. 



the mrtaoarpal of the little finger. It is a true pisiform bone, 

 iiltlniiiKh a tit.tli- descended. Between that which is on the metacarpal 

 of the thumb and the radius there is for a long time nothing but liga- 

 and one does not nee the great semilunal scaphoidal which 

 may be observed in the other sub-genera : but with age a small radial 

 bone shown itself in thin place. Very large individuals have also the 

 two penultimate bones of the second row anchylosed together. The 



metacarpal of the thumb is short and large : the others are long and 

 slender. The little finger has two phalanges, and is not larger than 

 the thumb ; the three others are elongated, especially the middle 

 finger ; and the whole result is a pointed hand, which has the unguial 

 phalanx of the thumb and forefinger only armed with a claw. 



In the Land-Tortoises there are but two phalanges on each finger. 

 There are found in the carpus a great radial or semilunar scaphoidal, 

 two ulnar bones nearly square, five bones of the second row sup- 

 porting the five metacarpals, and an intermediate bone placed between 

 the great radial, the first cxibital or ulnar, and those which carry the 

 third and fourth metacarpal. This intermediate bone, according to 

 Cuvier, is often anchylosed with the semilunar scaphoidal bone. 

 The bones of the metacarpus are even shorter than the phalanges. 



In the Fresh-Water Tortoises the three mesial fingers have their 

 three phalanges well developed ; but there are only two belonging to 

 the thumb and the little finger. The metacarpals are rather long, 

 and the two external ones are carried on a single bone of the carpus : 

 nevertheless the last row consists also of five bones, because there is 

 one, very small, externally on the side of the thumb. In the first 

 row the ulna, in the European Tortoise at least, carries four bones 

 two large ones, a small intermediate one, and another small one out 

 of the rank ; but there are other species, TfStudo clausa for instance, 

 where the two small ones do not appear. The great radial or semi- 

 lunar scaphoidal passes partially under the two uluar bones. 



The Chclydes have the hand formed nearly like the Fresh-Water 

 Tortoises, except that their radial bone is small, and re-enters towards 

 the inside of the carpus at the side of the bone named by Cuvier 

 intermediate; and that the little finger has, like the three inter- 

 mediate ones, three phalanges. 



The Trionycft have also the radial bone re-entering at the side of 

 the intermediate bone. Their first three fingers have their three 

 phalanges large, wide, and pointed to carry the claws ; the fourth has 

 four phalanges, all rather slender ; and the last three. 



Hind Feet. Cuvier remarks that in the Chelonia, generally, the 

 calcaneum is without any backward prominence, so that their tarsus 

 is flat like a carpus. 



In the C'helona it is composed of six or seven bones, if the first of 

 the little toe be counted : two in the first row, of which the largest, 

 nearly rhomboidal and answering equally to the tibia and fibula, is 

 the astragalus ; the smaller, which is square and articulated only to 

 the fibula, is the sole vestige of a calcaneum. In the second row there 

 are four : three wedge-shaped for the metacarpals of the great toe 

 and the two next toes, and one larger for the two last metatarsals. 

 The bones of the metatarsus of the great and little toes are shorter 

 than the others, and singularly wide and flat. That of the little toe 

 however may be taken for one out of the rank of the tarsus. In this 

 last case the little toe would have but two phalanges, otherwise three 

 like the others. The great toe has but two. It carries a claw, and 

 so does the next toe. The two succeeding toes have still their last 

 phalanges rather large, although without claws, but the last has that 

 phalanx very small. 



In the Land-Tortoises the bone analogous to the astragalus is larger 

 and thicker ; and the fibular bone on the analogue of the heel is 

 smaller. The four other bones exist, and that here called the meta- 

 tarsal of the little toe seems to make up the suite by its position and 

 figure. It sometimes carries a vestige of a toe formed of one piece, 

 which seemed to Cuvier to be wanting in many species. The rneta- 

 tarsal of the great toe is very short and not flattened ; the others are 

 rather longer. None of the four existing toes has more than two 

 phalanges. 



The tarsus of the Fresh-Water Tortoises is nearly the same, except 

 that the fibular ossicle, or calcaneum, when it is not united to the 

 astragalus, is larger ; that the ossicle which serves as a vestige of the 

 little toe is longer ; and that the three toes which succeed the great 

 toe have their phalanges very distinct. 



In the tarsus of the Trionyces the fibular bone descends outside the 

 three cuneiform or wedge-shaped bones, and carries half the head 

 of the third rnetatarsal and the whole of that of the fourth. At its 

 external border a large square bone adheres, that about which Cuvier 

 expressed a doubt whether it was a metatarsal bone or one out of 

 the rank. It carries the fifth metatarsal on the first phalanx of the 

 little toe ; but in this case the little toe would have three. It is true, 

 Cuvier adds, that the fourth toe has four, without counting its meta- 

 tarsal. The great toe has two, and the two succeeding toes three 

 each. In all three the last is large, wide, and pointed to carry a claw. 

 In the fourth and fifth toe this last phalanx is very small and without 

 a claw. 



In the Matamatn (Chelys) the fourth toe is, like the two preceding, 

 composed of three phalanges, and armed with a claw ; the fifth also 

 has three phalanges, and it would even have four if one regarded the 

 bone as to which Cuvier has expressed his doubts as a tarsal bone ; but 

 the last is very small, cartilaginous, and without a nail. The tarsus 

 is the same as in Trionijx, with this difference that the analogues of 

 the astragalus and the calcaneum are divided transversely each into 

 two bones ; so that what is detached from the calcaneum forms ;i 

 fourth cuneiform bone for the fourth metatarsal, and that which is 

 detached from the astragalus is a true scaphoid, which carries the 

 first three cuneiform bones. 



