THE CEOCODILIA. 257 



the ulnar proximal carpal and the second, third, fourth, 

 and fifth metacarpals, the thi-ee last of whicli it supports 

 altogether. On the radial side, a disk of cartilage, which 

 never becomes completely ossified, is connected by ligament 

 with the lenticulare, and is interposed between the radial 

 proximal bone and the head of the metacarpal of the pollex. 

 From the ulnar side of the head of this bone a cartilagi- 

 nous ligamentous band proceeds, over the head of the 

 second metacarpal, to the radial side of the lenticulare. 



The three radial digits are much stronger than the two 

 ulnar, and the numbers of the phalanges are 2, 3, 4, 4, 3, 

 counting from the radial to the ulnar side. 



The pelvis (Fig. 78, C) possesses large ilia, which are firmly 

 united with the expanded ends of the strong ribs of the 

 sacram. The ischium unites with its fellow in a median 

 venti'al symphysis, and, with the ilium, forms almost the 

 whole of the acetabulum. 



The pubes take hardly any share in the formation of the 

 latter cavity in the adult. Their axes are directed forwards 

 and inwards, and they coalesce in the middle line ; but as the 

 inner, or median, moiety of each pubis remains cartilaginous, 

 or imperfectly ossified, the bones, in imperfectly prepared 

 skeletons, appear as if they formed no symphysis. 



The tarsus presents, proximally, an astragalo-navieular 

 bone and a calcaneum, which are less closely united than in 

 the Lizards. The latter bone has a large calcaneal process 

 on its posterior face, the Crocodile being the only Sauropsid 

 vertebrate in which suchaprocess is developed (Fig. 78, 0. Ca.) 



Two rounded distal tarsal bones, of which the fibular is 

 much the larger, lie between the calcaneum and the third, 

 f oui'th, and rudimentary fifth, metatarsals. A thin plate of 

 cartilage is interposed between the distal end of the astra- 

 galo-navieular and the second metatarsal, and unites with 

 the head of the first metatarsal. 



As in the manus, the three, pre-axial, clawed, digits are 

 stronger than the others. The Mzh is represented only by 

 an imperfect metatarsal. The numbers of the phalanges are 

 2, 3, 4, 4, counting from the tibial to the fibular side. 



s 



