352 HENRY LESLIE OSBORN. 



also found later in the same year in the throat of the little blue 

 heron (Ardea herodias). Nebish is a small camping place situated 

 on the St. Mary's River, about twenty-five miles below the 

 outlet of Lake Superior. A new locality was thus added to the 

 distribution of the worm though one in the same river system 

 as the Canadian ones. 



In 1903 I received, through the kindness of Professor Linton, 

 some pieces of the small-mouthed black bass infected with this 

 parasite. The fish had been taken by the Rev. J. H. Young at 

 Troy, Ohio, on the Miami River, a tributary of the Ohio, and 

 part of the Mississippi system. Some of the worms were encysted 

 in muscle, but others were located in the skin on the internal 

 aspect of the branchiostegal membranes. Their location is 

 shown in Fig. I of this article. 



In the same year my attention was called by Dr. W. S. Nicke- 

 son, of the University of Minnesota, to certain flukes which he 

 had found in frogs, and they were at once recognized as specimens 

 of this species. At about the same time I began to notice them 

 in the frogs of this region brought to the laboratory for use as 

 biological material. The details of the occurrence of the fluke 

 in this region is still under investigation in connection with a 

 study of the parasites of the frogs of this vicinity, so that a fuller 

 account of this part of the subject is reserved for a later occasion. 

 It is important, however, to place on record the occurrence of the 

 fluke in this region, as it extends the range of the parasite con- 

 siderably beyond formerly recorded limits. 



The latest appearance of this form in literature is the record 

 of its recognition in the yellow perch of the Montreal markets 

 by Stafford in 1904, where it is given Leidy's designation Clino- 

 stomum gracile. 



The foregoing facts show that this species is very widely 

 distributed in this country, having been recognized at Kansas 

 City on the West and at St. Paul, Michigan, and as far east as 

 Montreal. It has been seen as far north as St. Paul and as far 

 south as Philadelphia and in Ohio in the center of this territory. 

 The occurrence at Porto Rico is anomalous and cannot be con- 

 sidered until more information is forthcoming. In view of the 

 wide distribution and large size of this species, it seems strange 



