294 



THE SPOROZOA 



Fio. loo. 



dr. 



S. masovica, Colin, is found in the gall-bladder of the bream (Abramis 



brama\ and S. eleyans, The"!., from Gasterosteus spp., penetrates from the 

 kidney into the ovarian stroma. Genus 4. Myxidium, 

 Biitschli. The spores are elongated in the sutural 

 plane, and fusiform, with a polar capsule at each 

 extremity (Fig. 107). The polar filaments are long 

 and filiform. About seven species are known, the 

 most familiar being M. Heberkiihnii, Biitsch., from the 

 urinary bladder of the pike. The other species are 

 mostly from the kidneys or gall-bladders of fishes, but 

 M. danilewskyi, Laveran, has been described from the 

 P.) kidneys of tortoises. Genus 5. Sphaeromyxa, Thel., 1892. 

 1( The spores are fusiform and longitudinally striated, 

 with truncated ends, and with a polar capsule at each 



extremity (Fig. 95). The polar filaments are short and conical. The 



trophozoite is generally of disc- 

 like or lenticular form, with lobed 



ectoplasm at the margin. Three 



species are known from the gall- 

 bladders of fishes. Genus 6. Cysto- 



discus, Lutz., 1889. Spores oval, 



with the sutural plane running 



obliquely to the principal axis, 



and a polar capsule placed near 



each extremity of the spore, but 



not quite terminal. Trophozoite 



similar to that of Sphaeromyxa. 



One species, C. immersiis, Lutz., 



from the gall-bladder of Bufo agua 



and Cystignathus ocellatus, in Brazil. 



[By Gurley the species Chloro- 



myxum diploxys, The"!., is also in- 

 cluded in this genus, which is 



made the type of a family Cysto- 



discidae. The genus Sphaeromyxa, 



Thel., is also referred by him to 



Fio. 107. 



Myxidium lieberkuhnii, Exit- 

 schli, from the urinary bladder 

 of the pike. a, trophozoite 

 with two spores and pseudo- 

 podia, after Lieberkiihn. ft, tro- 

 phozoite with numerous spores. 

 c and rf, spores, the latter with 

 extruded polar filaments. 6, c, 

 and d, after Balbiani. (From 

 Wasielewski.) 



this family, but doubtfully. By 



Thelohan, on the other hand, 



Cystodiscus immersus is referred to 



the genus Sphaeromyxa, and the 



genus Cystodiscu* is not recognised.] 



Genua 7. Myxosoma, The"!., 1892. 



The spores are flattened, and oval 



in outline, with the polar capsules cloie together at the anterior ex- 



tremity. One species, M. dujardini, The"l. (placed by Gurley in the genus 



Chloromyxum), from the gills of Scardinius erythrophthalmus and Leuciscut 



rutilus. Genus 8. Myxoproteus, Dofl., 1898. Spores roughly pyramidal, 



with spiky projections at the upper emd (i.e. from the base of the pyramid), 



which bears two large polar capsules, separated by an interval equivalent 



