Proceedings of the Boston Society of Natural History. 
VoL; XXEX.: No: 6— Aveuar, 1999. 
CONTRIBUTIONS FROM THE GRAY HERBARIUM OF 
HARVARD UNIVERSITY 
a 
New Sertes.— No. XVII. 
By B. L. Ropinson AND J. M. GREENMAN. 
I. Revision of the genus Gymnolomia. 
II. Supplementary notes upon Calea, Tridax, and Mikania. 
