DEFINITIONS OF SYSTEMATIC NAMES 421 



Ungulates, order of mammals which walk Xenopus, genus of tongueless toads from 



on the tips of the toes; horse, cattle, Africa. 



deer, antelope, etc. 

 Urodeles, order of tailed amphibia. Zeuglodon a genus of extinct whales 



(Cetacea). 

 Varanus, genus of lizards from Africa. Ziphius, genus of toothed whales. 



Xenarthra, sub-order of American eden- 

 tates, ant-eaters and armadillos. 



