308 



THE RABBIT 



the scaphoid, and forming the support for the second meta- 

 ca;rpal), the os magnum (articulating with the semilunar, 

 and supporting the third metacarpal), and the outer unciform 

 (composed of the fused fourth and fifth distal carpals, articulat- 

 ing with the cuneiform, and supporting the fourth and fifth 

 metacarpals). A small bone, the pisiform, articulates with 

 the cuneiform and the ulna. Between the proximal and distal 

 rows of carpal bones lies the os centrale, between the semilunar 

 and the os magnum. 



(e) The manus or hand, consisting of five metacarpals bearing five clawed 

 digits. Each digit has three phalanges, except the preaxial poUex 

 (thiunb), which has only two. 



Make a sketch of the fore-limb. {See Fig'. 103, page 306.) 



3. The Pelvic or Hip Girdle. 



Note that the pelvic girdle articulates with the sacrum. Free the girdle 

 from the sacrum, and note the following parts : — 



The pelvis consists of two lateral halves, the innominate bones, the long axis 

 of which is almost parallel with that of the vertebral column. Anteriorly and 

 internally they unite with the fused transverse processes of the sacrum by a 

 rough surface ; ventraUy they are connected together by cartilage at the pelvic 

 symphysis. On the outer surface of each innominate bone, at about the middle 

 of its length, is a deeply concave cup, the acetabulum (completely ossified). 

 Each innominate bone consists of : — 



(a) The ilium, which articulates "with the sacrum, a flattened bone forming 



Ilium- 



Acetabulum. 



Ischium 



Pig. 104 The Rabbit {Lepus cuniculus). A. The Sacrum and the Pelvic Girdle 



(Doraal view) ; B. The Right Innominate Bone (Lateral view). 



