64 THE ROYAL SOCIETY OF CANADA 
of the sucker, is possibly fatal to this host. 
It is believed that the blood parasite has been brought over to 
Canada in the German Carp. The parasite of the urinary bladder 
of the pike, Myxidium leberkuhni is identical with the parasite of 
the pike in Europe. These two cases indicate the possibility of fish 
diseases being introduced with fish brought over from Europe and the 
spread of the parasite to purely Canadian fishes. 
The parasite forming cysts in the muscles of the minnow Pime- 
bhales notatus is a new species. 
2. METHODS 
In searching for parasites the external surface and gills were first 
gone over carefully. The fish was then opened and the viscera were 
examined macroscopically. In some cases the blood from the heart or 
gills and the contents of the urinary and the gall bladders were 
examined in fresh preparations under the microscope. The following 
table gives a list of the fishes searched and the parasites found in 
them. 
In the case of the trypanoplasm found in the sucker, in addition 
to fresh preparations of the blood, smears were fixed in the vapour 
of osmic acid, dried, stained with Giemsa’s azur-eosin and mounted 
in Canada balsam. The myxosporidian parasites were studied in 
fresh preparations, ‘‘wet’’ smears fixed in Schaudinn’s fluid and stained 
either in Delafield’s haematoxylin or Giemsa’s azur-eosin and sections 
of infected tissue fixed in Schaudin’s fluid, cut in paraffin and stained 
with Delafield’s haematoxylin, Heidenhain’s iron haematoxylin, or 
Giemsa’s azur-eosin. For further details of the methods used see 
Mavor (:15). 
3. DESCRIPTIONS OF PROTOZOA FOUND 
A. Haemoflagellates 
Trypanoplasma borreli, Laveran et Mesnil ? 
As seen in the living state in fresh preparations of the blood of 
the common sucker, Catostomus commersonii, Lacépède, this trypano- 


? A more detailed description of this parasite and discussion of its identity has 
been already published by the author (Mavor, 1915a). 
