128 ILLINOIS BIOLOGICAL MONOGRAPHS [366 



at the posterior margin, where a few folds (three are figured) are seen. Two 

 oval polar capsules convergent and of equal size. Sporoplasm is sharply 

 contoured, no iodinophilous vacuole being recognized. Dimensions in 

 preserved material (?) : diameter 6.3 to 7n, thickness 4.2 to 4. 9m, length 

 of polar capsule 2.8 to 3.5^1. 



Family MYXOBOLIDAE Thelohan 



1892 Myxobolidees Th61ohan 1892 : 173, 176 



1893 Myxobolidae Gurley 1893 : 412, 413 

 1895 Myxobolidees Thelohan 1895 : 347 



The characters of the family are described on page 58. 



Genus MYXOBOLUS Biitschli 

 1882 Myxobolus Butschli 1882 : PI. 38 : 6-10 



The characters of the genus are described on page 58. 

 Type species: Myxobolus mulleri Butschli. 



MYXOBOLUS MULLERI Butschli 



Habitat: Air bladder and branchiae of Leuciscus cephalus L.; kidney 

 and ovary of L. phoxinus L.; eye of Crenilabrus melops L. and Alburnus 

 lucidus; branchiae of As pro as per L., Barbus vulgaris Flem., Leuciscus ruti- 

 lus L., Squalius cephalus L., S. agassizii Heckel, Lota vulgaris L., Phoxinus 

 loevis Ag.; pseudobranchiae of Coitus gobio L.; intestine of Mugil auratus 

 Risso.; France, Germany [Karlsruhe, AUe (October), Pregel, Frisches 

 Haff], Switzerland (Neuchatel Lake), Italy (Napoli, September). 



Vegetative form: White cysts in the connective tissue. Form elongated 

 oval, 2 to 3mm. in diameter. No clear differentiation of protoplasm is 

 observed even in young forms. In sections, some cysts show radiate 

 striations in the thick granule-free ectoplasm. Endoplasm filled with nuclei. 



Cepede writes as follows: Cysts in branchiae, subspherical or elliptical, 

 1.5mm. by 0.5mm. 



Wegener's form: Cysts small and rounded, 0.2 to 0.3mm. in diameter. 



Spore: Ordinarily spherical or subspherical. Two polar capsules 



