242 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 
63. Myxobclus transovalis Gurley, 1893. Pl. 29, fig. 1. 
Bull. U. 8. Fish Com. for 1891, x1, p.415; ib., Braun, 1894, Centralbl. f. Bakt. 
u. Parasitenkde, Xv, p. 87. 4 
Cyst.—Existence not evident, the spore-mass appearing to be held 
together by a small soft gelatinous or mucoid mass which has no attach- 
ment to the subjacent connective tissue, as if invariably comes away 
with the scale. It forms a thin discoidal mass situated in the center 
of the concave under surface of the scale. When at its thickest it 
elevates the scaie slightly, and this elevation is the principal guide to 
its detection. In addition its color when coagulated is a slightly deeper 
yellow than that of the surrounding tissues. Itis exceedingly difficult, 
in fact nearly impossible, to detect its presence in the fresh state. 
Myxosporidium unknown. 
Spore.—Length, 6 uw; breadth, 8 uw; shell thin; substance almost per. 
fectly transparent, insoluble in concentrated sulphuric acid, bivalve; 
the valves superior and inferior in position, equally ventricose, with a 
narrow ridge; valves separating easily when placed in cold concentrated 
sulphuric acid, also sometimes in strong glycerin, or when the mass is 
rolled under the cover slip. 
Capsules: Two, of equal size, containing a coiled filament extruded 
under the influence of glycerin and of sulphuric acid; capsular index 
about 0-50. 
Sporoplasm: The great convexity of the sporoplasm renders it diffi- 
cult of determination whether the deeper iodine-stained portions rep- 
resent merely greater thickness or a vacuole. Sometimes the latter 
view was suggested by the rather sharp outline of such deeper-stained 
areas. Hydrochioric acid alcohol carmine stains 2 (very rarely 1 only) 
comparatively large (1 to 1°5 yz in diameter) nuclei, which are always 
and plainly situated in the sporoplasm with a site by preference along 
or near one of its concave anterior borders; pericornual nuclei appar- 
ently absent. 7 
Hahbitat.—Under scales on external surface (mostly on posterior half) 
of Phoxinus (Olinostomus) funduloides Girard, taken in 4-mile Run (trib- 
utary of Potomac River), near Carlins, Va., June 29, 1892; collector, the 
author. Among fishes collected from the same locality, August 29, 
1892, no diseased specimens were found. 
64. Myxobolus ? merlucii Perugia, 1891. Pl. 29, figs. 2-7. 
Myzxosporidium merlucit Perugia, 1891, Boll. Scientif., Pavia, x11, pp. 22, 24, 
figs. 9-14; Myaxobolus merluccii [error], Thélohan, 1892, Bull. Soc. philomat. 
Paris, 1v, pp. 166, 178; AZ. merlucii, Gurley, 1893, Ball. U. S. Fish Com. for 
1891, x1, p. 415; ib., Braun, 1894, Centralbl. f. Bakt. u. Parasitenkde, xv, 
p. 87. 
Myxosporidium.—Occurring under various forms; no differentiation 
of ectoderm; no pansporoblast membrane. The spores are expelled at 
their maturity from the myxosporidium. Perugia adds: 
I have also seen form 2 contiguous vacuoles which do not present the slightest 
trace of capsules, but only a few granulations. 
