THE RABBIT. 283 



the acetabulum, 1 a deeply concave articular surface on 

 the external face of the innominate bone. The ilium 

 presents a ventral (pre-axial) pubic border, a dorsal 

 (post-axial) ischial border, an external acetabular 

 border consisting of an inconspicuous ridge running from 

 the acetabulum along its outer surface, and an anterior 

 (dorsal) supra-iliac border along its free end : that portion 

 of its external surface on the ventral side of the acetabular 

 border is the iliac fossa, that on its dorsal side the 

 gluteal fossa ; its inner surface is the sacral fossa. 

 The pubes of opposite sides unite with one another in 

 the middle line, by synchondrosis, to form the symphysis 

 pubis : the posterior part of the ischium is expanded and 

 roughened, forming its tuberosity (tuber ischii). 



92. If the hind-limb be compared with that of the Lizard 

 (p. 151 § 108), it will be seen that the femur, and with it 

 the whole limb, has undergone rotation forwards : as a con- 

 sequence of this the hind-Hmb is, like the fore-limb, 

 brought into a plane parallel with the median vertical plane 

 of the body, but, the rotation being in the opposite direc- 

 tion, the pre-axial border is internal in the whole limb, and 

 the originally dorsal surface looks, on the v.hole, forwards. 



93. The femur, the long axis of which, in the natural 

 position, is directed downwards and forwards, so that its 

 originally dorsal surface looks upwards and forwards, and its 

 pre-axial border inwards. Its proximal extremity presents 

 a rounded, projecting head on its pre-axial (inner) border, 

 for articulation with the acetabulum ; a large process, the 

 greater trochanter, just external to the head; a pit, the 

 trochanteric fossa, on the ventral surface, bounded 

 pre-axially by the great trochanter ; a lesser trochanter 



^ The pubis proper is really shut out from the acetabulum by a ssnall 

 epiphysis, the cotyloid boue. 



