Proceedings of the Boston Society of Natural History. 
Vout. XXIX. No. 5.—Aveust, 1899. 
ISSUED. 
AUG 24 1899 
CONTRIBUTIONS FROM THE GRAY HERBARIUM OF 
HARVARD UNIVERSITY. 
NEw Series. — No. XVII. 
By B. L. Roprnson anp J. M. GREENMAN. 
I. Revision of the genus Gymnolomia. 
Il. Supplementary notes upon Calea, Tridax, and Mikania. 
