LETTER OF TRANSMITTAL. 
U. S. DEPARTMENT OF AGRICULTURE, 
DIVISION OF BOTANY, 
Washington, D. C., March 24, 1894. 
Sir: I have the honor to transmit herewith, for publication as Vol. 
il, No. 2, of Contributions from the U. S. National Herbarium, a Pre- 
liminary Revision of the North American species of Cactus, Anhalonium, 
and Lophophora, by President John M. Coulter. 
Respectfully, 
FREDERICK V. COVILLE, 
Chief of the Division of Botany. 
Hon. J. STERLING Morton, 
Secretary of Agriculture. 
