THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 167 
Variety 3.—(Robin’s plate 15, figs. 3; 5a, b; 8.) 
Microscopie.—Cells regularly or irregularly ovoid, alittle smaller than 
those of the first variety, brownish yellow, presenting a peculiarity 
found in no animat cell, viz, a round opercle.! Cells unaffected by 
acetic and nitric acids, and by ammonia. 
Macroscopic.—Colonies of variety 3, consisting of small lenticular, or 
irregular brown or white masses scattered here and there at the base 
of or below the lobes, and especially over the submucous surface of 
the parasitic convoluted-string mass. 
(1) Brownish masses.—2 to 4 mm. thick, composed of masses or 
colonies of irregular, cupped, operculate cells, the whole enveloped by 
a layer of cellular tissue containing very fine capillaries, Masses some- 
times sufficiently numerous to color quite an area of the mucosa black- 
ish brown. Further, when the convoluted-string mass is absent, brown 
bodies may occur in the same situation. These bodies are ordinarily 
accompanied by small pea-sized,whitish corpuscles, composed of round 
granules measuring about 0:20 mm., formed of strongly united fibers of 
cellular tissue wound around a small transparent, apparently calcareous, 
body. It contains in the center 1 to 8 or 12 cells, furnished with an 
opercle similar to that above described. 
(2) Whitish masses.—Composed of grains formed of 2, 3, 4, or 12 
(rarely 1) cells, surrounded by a thick cellular tissue layer, the fibers of 
which are strongly united by amorphous finely granular matter, the 
whole forming rather hard, white, spherical or ovoid grains, § to 4 mm. 
in size, often clearer in the center. 
Calecareous granules forming an oval or circular mass (fig. 5) with 
sharply defined borders (the latter sometimes split); granules forming 
whitish, more or less flattened, friable, irregularly lobulated, pea-sized 
miliary masses. Granular mass destitute of vascularity, the vessels 
being confined to the tissue sheath. 
Some masses are hard, yellowish white, of variable form, composed 
of operculate cells, calcareous granules, and a great number of very 
large, quadrilateral or rhomboidal, tabular crystals, the latter often 
piled up,insoluble in acetic acid,in which only the calcareous granules 
disengage some bulle of gas. Caleareous granules also occur without 
crystals, being in this case whiter and less yellowish. 
The convoluted string (cordon enroulé).—As described above, the cells 
of varieties 1 and 2 form continuous (endless) cylindrical filaments, 
those of variety 1 forming yellow filaments, those of variety 2 forming 
white filaments. The convoluted string is usually? formed of 6 of these 
1Robin gives the size of the opercle as 0:06 mm., but as he says the cells are smaller 
than those of the first variety (whose length is 0:027 mm.) this must be an error, pos- 
sibly for 0:006 mm. 
2Sometimes, however, only 2 filaments (instead of 6) are present, viz, 1 large 
yellow filament (instead of 2), and 1 (not 4) thin white filathent. Also (very rarely) 
the convoluted string contains only 1 (instead of 6) white filament (variety 2) and 
2 or 3 successive enveloping sheaths. 
