58 ILLINOIS BIOLOGICAL MONOGRAPHS [296 



Genus MYXIDIUM Butschli 1882 



Spores more or less regularly fusiform, with pointed or rounded ends. 

 Polar filaments long and fine. 26 species. Monosporous, disporous and 

 polysporous. 22 in body-cavity; 4 in tissue. 15 in marine and 6 in fresh- 

 water fish, 2 in fishes from both waters and 3 in reptilia. Type species: 

 Myxidium lieberkiihni Butschli. 



Genus SPHAEROMYXA Thelohan 1892 

 Spores fusiform, with truncated ends. Polar filament short and thick. 

 Trophozoites large and disc shaped. 7 species. Polysporous (2 unknown). 

 6 in body-cavity; 1 unknown. 6 in marine fish; 1 in amphibia. Type 

 species: Sphaeromyxa balbianii Thelohan. 



Genus ZSCHOKKELLA Auerbach 1910 

 Spores, semicircular in front view; pointed at ends. Polar capsules 

 large and spherical, opening on the flat edge near the tips. Sutural line 

 usually curved in S-form. 4 species. Monosporous, disporous and poly- 

 sporous. Body-cavity. 2 from marine and 2 from fresh-water fish. Type 

 species: Zschokkella hildae Auerbach. 



Family MYXOSOMATIDAE Poche 1913 

 Two polar capsules at the anterior end. Sporoplasm without iodino- 

 philous vacuole. 



Genus MYXOSOMA Thelohan 1892 

 Spores ovoidal, flattened and more or less elongated. 3 species. Poly- 

 sporous. Tissue parasites. 2 in fresh-water and 1 in marine fish. Type 

 species: Myxosoma dujardini Thelohan. 



Genus LENTOSPORA Plehn 1905 

 Spores similar to Myxobolus in form. Sporoplasm without any iodino- 

 philous vacuole. 6 species. Disporous and polysporous (2 unknown). 1 

 in marine and 3 in fresh-water fish, 2 from fishes in both waters. Type 

 species: Lentospora cerebraUs (Hofer) Plehn. 



Family MYXOBOLIDAE Thelohan 1892 

 Spores with one or two polar capsules at the anterior end, with or 

 without posterior processes. Sporoplasm with an iodinophilous vacuole. 

 Majority polysporous in fresh- water fishes. 



Genus MYXOBOLUS ButschU 1882 

 Spores ovoidal or ellipsoidal; flattened. One or two polar capsules at 

 the anterior end. Shell without posterior process. 63 species. Poly- 

 sporous (9 species unknown). 59 species in tissue; 4 unknown. 5 in 

 marine and 56 in fresh-water fish, 1 in annelid and 1 in amphibia. Type 

 species: Myxobolus mUlleri Butschli. 



