TREASURY DEPARTMENT. 
Public Health and Marine-Hospital Service of the United States. 
i Walter Wyman, Surgeon-General. 
HYGIENIC LABORATORY -BULLETIN No. 17. 
Tvl. J. ROSEiJMAU, Director. 
August, 1904. 
ILLUSTRATED KEY 
TO THE 
TREMATODE PARASITES OF MAN. 
ma 
CH. WARDE^LL STILES. 
