282 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
Concerning this species Biitschli says: 
Balbiani has observed cysts in the body cavity of a butterfly (Pyralis viridiana) 
which were filled with corpuscles possessing a structure similar to that of the myx- 
osporidian spore. The observation is, however, not sufficient to demonstrate that it 
belongs to the Myxosporidia. 
Thélohan and Henneguy regard it as a myxosporidian, and itis diffi- 
cult for me to think otherwise. 
VIII. SPHAZXROMYXA Thélohan, 1892. 
Etymology not given. 
Compt. Rend. Acad. Sci. Paris, cxv, p. 1093; ib., Brann, 1893, Centralbl. f. Bakt. 
u. Parasitenkde, Xv, p. 737. 
Definition.—Characters to be inferred from those of the type species, 
S. balbianti. 
After several vain attempts to draw up a satisfactory generic defini- 
tion as between this genus and Cystodiscus, | have concluded that at 
present there are not in the record sufficient data for their accurate 
delimitation. 
99. Spheromyxa balbianii Thélohan, 1892. 
Compt. Rend. Acad. Sci. Paris, Cxv, pp. 1091-3; ib., Braun, 1893, Centralbl. f. 
Bakt.u. Parasitenkde, xv, p. 738. 
Myxosporidium.—Generally visible to the naked eye as a small 
opaque, more or less regular, usually subspherical mass, occupying a 
variable part of the bladder and escaping with the bile; yellowish or 
greenish-yellow, of a relatively firm consistence, permitting of handling. 
Attempts at teasing render evident the presence of a thin membrane. 
Under the microscope the myxosporidium shows absolutely exceptional 
characters. Ectoplasm forming a clear, homogeneous zone, presenting 
in sections a very clear striation. Hndoplasm more granular, inclosing 
numerous spores. 
Spore.—Resembling that of Myxidiwm lieberkiihnii, elongate, slightly 
swollen at middle; extremities abruptly truncate, cut squarely off, so 
to speak, so as to present very sharp “lateral” angles; “length” [?] 138 to 
16 uw; “breadth” [?] 5 uw. Shell bivalve, finely striate, parallel to the 
longer axis. Capsules 2, one at each “extremity,” their axes oblique 
and oppositely directed with reference to the longer [transverse ?] diam. 
eter of the spore. Filament very peculiar, forming a relatively very 
short (average length 15 x) cone, the diameter of whose base nearly 
equals the breadth of the extremity of the spore. Exit produced by 
iodine water, potassium hydrate, sulphuric acid, etc. The mode of coil- 
ing is equally peculiar, the axis of the coil being perpendicular to the 
long axis of the capsule. Sporoplasm forming a single mass, destitute 
of an iodinophile vacuole; nuclei, 2; the pericornual nuclei (Thélohan’s 
“nuclei of the capsulogenous cellule”) are also present. 
Habitat.—Free in the gall bladder of Onus tricirratus and O. macu- 
latus (= Motella trictrrata and M. maculata); very common, especially at 
Roscoff. 
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