292 THE PELVIC GIRDLE. [chap. 



Order Ungulata. — In the Pecora the pelvis generally is 

 elongated. The ilium is expanded and everted at the 

 upper extremity ; but between the sacral attachment and the 

 acetabulum it is much contracted, and its borders rounded, 

 so that the divisions of its surfaces are no longer distinct. 

 There is usually a deep oval depression above the ace- 

 tabulum, just within the attachment of the rectus muscle. 

 The anterior outlet forms a regular oval with the long 

 diameter between the sacrum and symphysis. The latter 

 is very long, including a considerable portion of the ischia. 

 The margins of the bones are completed by large epiphyses 

 in this region, but ultimately coalesce across the middle line. 

 The ischia are much developed ; the tuberosities are large, 

 and have on the middle of their outer side a well-marked 

 conical process, directed outwards, and very characteristic 

 of this group of animals. 



In the Giraffe the pelvis is shorter than in most of the 

 other Pecora ; the upper ends of the ilia are more expanded, 

 the thyroid foramen is nearly circular, and the supra-ace- 

 tabular fossa is almost obsolete. 



These characters are still more strongly marked in the 

 Camels ; while, on the other hand, in the Pigs the pelvis is 

 elongated, and much resembles that of the Pecora, but the 

 supra-acetabular fossa is wanting. 



In the Perissodactyla, the ilia are widely expanded above, 

 but much contracted on approaching the acetabulum. The 

 ischia are less elongated than in the Pecora, and the thy- 

 roid foramen is more circular. 



The Elephant has a very peculiar pelvis, the form of the 

 ilium, and the arrangement of its surfaces, somewhat recalling 

 those of the human pelvis. The supra-iliac border or crest 

 is greatly extended and curves outwards and downwards. 

 The sacral surface of the ilium is narrow, and scarcely rises 



