3o6 RESEARCH IN PROTOZOOLOGY 



Spores ellipsoidal ; circular in cross-section. With one polar capsule ; 

 without iodinophilous vacuole. 



Genus Coccomyxa Leger et Hesse, 1907 - 



Polar filament long. In organ-cavity of marine fish. Monosporous 

 and polysporous. Type species: Coccotnyxa morovi Leger et Hesse.' 



Family myxosomatid^ Poche, 19 13 emend.- 



Spores with two or four polar capsules at anterior end; with or with- 

 out posterior prolongation of the shell-valve. Sporoplasm without 

 iodinophilous vacuole. 



Genus Myxosoina Thelohan, 1892 

 Genus Lentospora Plehn, 1905 

 Genus Agarclla Dunkerly, 191 5 



Spores elongated ovoid; four polar capsules at anterior end. Pos- 

 terior end of shell-valves prolonged into long processes. Poly- 

 sporous. In testis of South American lung-fish. Type and only 

 species : Agarella gracilis Dunkerly.' 



Family myxobolid^ Thelohan, 1892 

 Genus Myxobolus Biitschli, 1882 

 Genus Henneguya Thelohan, 1892 

 Genus Hofcrelhis Berg, 1898 



'Recent studies by Dunkerly (1925) and Georgevitch (1926) indicate 

 that this genus should be included in myxosporidia. 



'Dunkerly (1915) held the number of polar capsules as a more important 

 character than the form of spore, and placed this genus in the family 

 CHLOROMYXiD.E. In a later paper (1925) in which he gave neither side view 

 nor thickness of the spore, Dunkerly writes that "in Kudo's classification 

 Agarella would come under the suborder sph^erosporea (an unfortunate 

 name, since many of the included genera are anything but spherical in 

 shape), and in the family chloromyxid^, the genus Chloroniyxum being 

 the only one known hitherto with four polar capsules." This is due to 

 misunderstanding on the part of Dunkerly. Since Dunkerly states that "the 

 form of the spore exactly resembles that of Henneguya" and that the spore 

 was "slightly flattened in the sutural plane," Agarella is clearly to be con- 

 sidered a platysporid myxosporidian with four polar capsules, and not a 

 spherosporid as Dunkerly designated. This is clearly to be seen from the 

 definitions of these suborders (Kudo, 1920:57). In microsporidia (Kudo, 

 1924), the writer placed the number of polar capsules above the form of 

 spore ; in myxosporidia, the form of the spore can be used with less con- 

 fusion as the basis of establishing the major subdivisions of the group than 

 the number of polar capsule. Since Dunkerly did not mention the presence 

 of iodinophilous vacuole in the spore, it is supposed that this was absent. 

 For these reasons the genus is placed in the family with a slight change 

 in the definition of the family. 



