Bulletin of the Museum of Comparative Zoology 
AT HARVARD COLLEGE, 
Vou. XXXVI. ~ No. 2: 
SOME NORTH AMERICAN FRESH-WATER RHYNCHO- 
BDELLIDH, AND THEIR PARASITES. 
By W. E. CASTLe. 
Wirn Erent PLATeEs. 
CAMBRIDGE, MASS., U.S. A.: 
PRINTED FOR THE MUSEUM. 
Avcust, 1900. 
