IISTDEX. 



435 



Xenodiaous, 156, 267. 

 Xenoneura, 146, 282. 

 Xiphodon, 382. 

 Xylobius, 151, 286. 



Yak, 379. 

 TeUow-hammer, 70. 



Zalophus, 391. 

 Zamenis, 321. 

 Zanclodon, 160. 

 Zaphrentis, 143, 151. 



Zapns, 858. 



Zarachia, 845. 



Zebra, 370. 



Zebu, 92. 



Zeuglodon, 344. 



Ziphius, 342, 345. 



Zoarccs, 294. 



Zonites, 160, 208. 



Zoological regiona, definition of, 66. 



ZoriUa, 390. 



Zygobatis, 300. 



