120 PELVIS AND HIND-LIMB OF THE CROCODILE. 



manifest a very close resemblance to it. The first bone, 

 called the " femur," is longer than the humerus, and, like 

 it, presents an enlargement of both extremities, with a 

 double curvature of the intervening shaft, but the direc- 

 tions are the reverse of those of the humerus, as may be 

 seen in Fig. 18, where the upper or proximal half of the 

 femur is concave, and the distal half convex, anteriorly. 

 The head of the femur is compressed from side to side, 

 not from before backwards, as in the humerus ; a pyra- 

 midal protuberance from the inner surface of its upper 

 fourth represents a "trochanter;" the distal end is ex- 

 panded transversely, and divided at its back part into two 

 condyles. The next segment of the hind- limb or " leg," 

 includes, like the corresponding segment of the fore-limb 

 called " fore-arm," two bones. The largest of these is the 

 " tibia," 66^ and answers to the radius. It presents a large, 

 triangular head to the femur ; it terminates below by an 

 oblique crescent with a convex surface. The " fibula" is 

 much compressed above ; its shaft is slender and cylin- 

 drical, its lower end is enlarged and triangular. The 

 group of small bones which succeed those of the teg are 

 the tarsals ; they are four in number, and have each a 

 special name. The " astragalus" articulates with the tibia, 

 and supports the first and part of the second toe. The 

 calcaneum intervenes between the fibula and the ossicle 

 supporting the two outer toes; it has a short but strong 

 posterior tuberosity. The ossicle referred to represents 

 the bone called " cuboid" in the human tarsus. A smaller 

 ossicle, wedged between the astragalus and the metatar- 

 sals of the second and third toes is the " ectocuneiform." 

 Four toes only are normally developed in the hind-foot 

 of the crocodilia; the fifth is represented by a stunted 

 rudiment- of its metatarsal, which is articulated to the 



