680 Wisconsin Academy of Sciences, Arts, and Letters . 
It has not been possible to decide whether or not the 
myxosporidium occurs attached to the walls of the urinary 
bladder. The occurrence in smears of myxosporidia im¬ 
bedded in masses of epithelial cells of the urinary bladder 
suggests that this may be the case (Fig. 1, b). 
The Systematic Position of the Parasite 
So far as the writers are aware the genus Henneguya con¬ 
tains eighteen species which are as follows (Auerbach 1910, 
Labbe, 1899, and Gurley, 1894): 
1. H . psorospermica Thel. 
2. H . media Thel. 
3. H. brevis Thel. 
4. H. schizura Gurley 
5. H. creplini Gurley 
6. H. linearis Gurley 
7. H. strongylura Gurley 
8. H. monura Gurley 
9. H. kolesnikovi Gurley 
10. H. macrura Gurley 
11. H. zschokkei Gurley 
12. H. sp. Borne 
13. H. sp. Clap. 
14. H. nusslini Schubert and 
Schroder 
15. H. acerinae Schrod. 
16. H. tenius Yaney et Conte 
17. H. legeri Cepede 
18. H. gigantea Nemeczek 
from Lucius lucius and Perea 
fluviatilis. 
“ Gasterasteus aculeaetus 
and G. pungitius. 
“ Gasterasteus aculeatus 
and G. pungitius. 
“ Lucius lucius 
“ Acerina cernua 
“ Pimelodus sebae and 
Platysoma fasciatum 
“ Synodontis schall 
“ Aphredoderus say anus 
“ Goregonus lavaretus 
“ Hybognathus nuchalis 
“ Cor eg onus lavaretus 
“ Leuciscus rutilus 
<s Leuciscus rutilus 
“ Truttafario 
“ Lucioperca lucioperca 
Acerina cernua 
“ Acerina cernua 
“ Cobitis barbatula 
“ Lucioperca sandra 
Henneguya wisconsinensis differs from Nos. 1, 2 and 5 in 
having a broader and less elongated spore, from No. 3 by 
the shape of the anterior end of the spore, from No. 4, 6, 8, 
9, 10, 11, 14, 15, and 18 in having shorter caudal filaments, 
from Nos. 7, 16 and 17 in having larger spores. The spores 
