[54] 
CONTRIBUTIONS TO AMERICAN 
HEUMINTHOLOGY. 
BY R. RAMSAY WRIGHT, M.A., B.S8c., 
Professor in University College, Toronto. 
No. 1. 
The observations recorded in the following pages were made for the 
most part during the months of September and October of the present 
year. Teaching duties have, however, prevented the completion of 
many of them ; and it is only in consideration of the difficulty of pro- 
curing, during the winter, fresh material with which these might be 
supplemented, and of the fact that certain other interesting forms 
(which I hope shortly to describe to the Institute) have recently 
engaged my attention, that I publish these notes in their present 
fragmentary condition. 
The work was undertaken with the desire of contributing towards 
a wider knowledge of the anatomy of Trematodes. In the attempt, 
however, to diagnose the forms that presented themselves for examina- 
tion, it became apparent that in spite of the extensive contributions 
of Dr. Joseph Leidy, much work of a faunistic character remains to 
be done in this department on this continent. 
The present paper has assumed in this way more of a systematic 
character than was originally intended; although there are, it is 
hoped, some points of interest to the general zoologist. 
Certain important memoirs are not accessible to me here; owing 
to which there are, no doubt, misstatements or omissions which might 
otherwise have been rectified. 
TREMATODES. 
lst Sus-OrpER—DIGENEA. VAN BEN. 
1,—DiIsToMUM HETEROSTOMUM, ud. 
I refer provisionally to this species certain worms which I have 
found on two occasions firmly adhering to the mucous membrane 
