Index to Genera. 



229 



Xanthoria 197 

 Xanthoxylum 68, 175 



Yucca 61 



Zannichellia 58 

 Zanthoxylon 68, 175 



Zea 200-202, 217-8, 220, pi. 19 



Zinnia 61 



Zizania 202, 217-9, pi. 1 7 



Zizyphus 174, 182, 188, pi. 13 



Zonites (80) 



Zygadenus 60-1 



Issued January 30, 1899. 



