U.S. DEPARTMENT OF AGRICULTURE, 
‘DIVISION OF BOTANY. 
CONTRIBUTIONS 
FROM 
THE U.S. NATIONAL HERBARIUM. 
Vol. Ill, No. 7. 
ISSUED APRIL 1, 1896. 
PRELIMINARY REVISION OF THE NORTH AMERICAN SPECIES 
OF ECHINOCACTUS, CEREUS, AND OPUNTIA. 
BY 
JOHN M. COULTER. 
WASHINGTON : 
GOVERNMENT PRINTING OFFICE. 
1896. . 
