MANUAL OF ZOOLOGY 



SECT. 



The pelvic arch (Fig. 280) contains the same elements 

 as in the Pigeon, but the union of the ilium with the sacrum 

 is less intimate, the acetabulum is not perforated, and the 

 pubes of opposite sides unite ventrally in a symphysis (sy.). 

 The ilium and ischium meet in the acetabulum or articular 

 cavity, which they contribute to form for the head of the 

 femur, but the remainder of the cavity is bounded, not by 



the pubis, but by a 

 small intercalated ossi- 

 fication the cotyloid 

 bone. The ilium (//.) 

 has a rough surface for 

 articulation with the 

 sacrum. Between the 

 pubis (pub.) in front 

 and the ischium (isch.) 

 behind is a large aper- 

 ture. the obturator fora- 

 men (obt.). The femur 

 has at its proximal end 

 a prominent head for 

 articulation with the 

 acetabulum, external to 

 this a prominent process 

 the great trochanter, 

 and internally a much 

 smaller lesser trochanter, 

 while a small process 

 or third trochanter is situated on the outer border a 

 little below the great trochanter. At its distal end are 

 two prominences or condyles, with a depression between 

 them. Opposite the knee-joint, or articulation between the 

 femur and the tibia, is a small bone or knee-cap $\Q patella. 



FIG. 280. Lepus cuniculus. Innominate 

 bones and sacrum, ventral aspect. acet. 

 acetabulum ; //. ilium ; isch. ischium ; obt. 

 obturator foramen ; pub. pubis (the reference 

 line should point to the side of sy) \ sacr. 

 sacrum ; sy. symphysis. 



