524 



Bulletin American Museum of Natural History. f\^ol. XXVII. 



Uropsilus, 263. 



Uterus, phylogenetic significance of, 411. 



Variability of characters in related 

 genera, 29. 



Vertebrae, 431; secondary increase in- 

 number, 431; cervical: Cynodonts, 

 118; Monotremes, 152, 155; dorso- 

 lumbars in primitive mammals, 275. 



Vesalius, 13; indirect influence on 

 mammalogy, 103. 



Vicq d'Azyr, 53. 



Viverravus (= Didymictis), 309, 311; 

 humerus figured, 437. 



Viviparous quadrupeds, 21. 



Vomer, 244. 



Wagner, 86. 



Weber, 4, 87, 89; classification by, 99. 



" Wedge Theory," of evolution of molars, 

 193. 



Whales, discovery of relationship with 

 terrestrial quadrupeds: 15 (Wotton), 

 20, 21 (Ray); 28, 33 (Linnaeus). 



Wortman, 89. 



W^otton, 14. 



Wynyardia, 214. 



Xenarthra, 339; genetic relations, 340. 

 Xenotherium, 258. 



Zalambdodonta Gill, 235; characters 

 and genetic relations, 236-268 ; primi- 

 tive characters (Solenodon), 254. 



Zeuglodontia Gill: taxonomic history, 

 411; genetic relations, 416-419. 



Zittel, 88. 



Zygomatic arch of Cynodonts, 120. 



