CASTLE: NORTH AMERICAN RHYNCHOBDELLIDA. 61 
spores. Data, accordingly, are wanting for a full description of this 
parasite, as well as of the others mentioned, and only a portion of its 
life history is known. Nevertheless I insert this notice in the hope 
that some one else may be able hereafter to make use of my fragmentary 
observations. 
CampBripeGs, Mass., June, 1900. 
