TEE POSTERIOR LIMBS. 127 



often absent ; however, its presence in a certain number of instances allows it to 

 be affirmed that Solipeds materially and virtually belong to the pentadactylous 

 type. This conclusion applies a fortiori to all the domestic animals. 



According to statistics drawn up by Cornevin, the return to the pentadacty- 

 lous type is much more frequently manifested, in Solipeds, in the anterior than 

 the posterior limbs. 



Article YI. — Posterior or Pelvic Limbs. 



Each of these is divided, as already noted, into four secondary regions : the 

 pelvis, thigh, leg, and foot. 



Pelvis (Figs. 83, 84, 85). 

 The pelvis is a kind of bony cavity formed by the union of the sacrum with 

 two lateral pieces — the ossa innominata, or coxae — which are consolidated with each 



Fig. 83. 



THE OSSA INNOMINATA (SEEN FROM BELOW). 



1, Iliac surface ; 2, auncular facet ; 3, angle or crest of the ilium ; 4, angle of the haunch ; 5, 

 ?eSs. r;^' V^"'\T '^'^'V*"' '\ °°^ ""^ '^' '"P'-'°'^ f""- tl^e insertion of the rec'tu 

 rator) foramen ; 11, sciatic spine ; 12, 12, ischiatic arch, r ) , ^, 



Other in the inferior median line. The description of the sacrum having been 

 ah:eady given, it now remains to speak of the os inn^ominatum of each side. 



A. Coxa, or Os Innominatum. 



The OS innominatum—2X^o designated os coxa, os iliacum, os innominatum-is 



a very irregularly shaped flat bone, double (with its fellow on the opposite side), 



and directed obhquely downwards and backwards. It is contracted in its middle 



part, which presents externally a deep cavity-the cotgloid ; anteriorly, where 



