THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Dark 
49. Myxobclius ellipsoides, Thélohan, 1892. Pl. i3, figs. 5, 4!; pls. 18, 20; pl. 19, figs. 
2-8; pl. 21, figs. 1, 3d, 5, (2? 2, 3a-c,c; ??4; ? pl. 22, figs. 1-3). 
Tench Pike, 
“psoro- | [Error] 
sperms” | ‘‘psoro- | Bais Date. Authority; reference. 
of, spores) sperms” | 2 
of, ete. of. 
| = 
| 
> lw Bacaeeeeee eeraneeccate | 1863 | Balbiani, Compt. Rend. Acad. Sci. Paris, LVIT, p.160. 
Se yay | CS eae a | ae ee 1864 | BYtibiani, Gaz. Méd., Paris, XIX, p. 146. 
ee lee Gy 1h eae ee ea 3 1874 | Moreau, Compt. Rend. Assoc. france. Avance. Sci., 2° 
| (Lyons) Sess., p. 814. 
Bg Seca ae Cee eee [evo eare ater 1883 | Balbiani, Journ. de Microgr., VII, pp. 199, 201-2, 
| | 272-4, 276-9, figs. 40, 61-3, 65a (see p. 211). 
x eves eisis am 2 eth ceo 1884 | Balbiani, Lécons sur les Sporozoaires, pp. 127-8, 130, 
| 137-40, 142-6, 148, figs. 36, 42-44, 46a; p).3, fig. 9; 
| | pl. 4, figs.1-8 (pars; see p. 211). 
x aac. Cees eee ess 1886 | Railliet, Elém. Zool. Méd. et Agric. Paris, pp. 167-8, 
| | fig. 72. 
eh eee oSCeteree 1887 | Pfeiffer, Ztschr. f. Hygiene, ITI, p. 475, fig. 2 e, f, g. 
x | x [eee Uae ot. z | 1888 | Pfeiffer, Ztschr.f. Hygiene, LV, pp. 409, 417-20, fig. 
| | 15 a-c. 
j < So SSSR SoEeene Se | 1889 | Henneguy, Dict. Encyclop. d. Sci. Méd., p. 775, figs. 
2a-h. 
A wai eee. eects | 3889 | ‘Phélohan, Compt. Rend. Acad. Sci. Paris, CLX, pp. 
920-1. 
Sot 8 NAIR sem sais bape a ee act | 1850 | Thélohan, Annal.de Microgr., II, pp. 198, 200-4, 
207, 209, 210, pl.1, figs. 2, 3, 12-16. | 
x lervsrsletetera ate [ose eee eeee ' 1899 | Thélohan, Compt. Rend. Acad. Sci. Paris, CXI, 
| } p. 695. 
So esp assed eee scopes 1890 Pfeiffer, Arch. f. pathol. Anat. u. Physiol., CX XII, 
| | pp. 558-9, 563. 
Se sae eee nen Naess 1890 | Pfeiffer, Die Protozoen als Krankheitserreger, 1 ed., 
pp. 44, 47, 48, figs. 14, 16 (part; all ?). 
Oats | eicceane eeeeta te 1891 | Pfeitier, Die Protozoen als Krankheitserreger, 2 ed., 
| pp. 130, 133-4, figs. 54, 56 (part; all 2). 
We aoe soti Myob- | 1892 | Thélohan, Bull. Soc. philomat. Paris, IV, p.177. 
| olus. 
pacecntges -.-do ....| 1893 | Gurley, Bull. U.S. Fish Com. for 1891, XI, p. 414. 
Sawai ote or '...do...-.| 1893 | Braun, Centralbl. f. Bakt. u. Parasitenkde, XV, 
| p. 739. 
et aciessck 2 ..-do..... 1894 | Braun, Centralbl. f. Bakt. u. Parasitenkde, XVI, 
| p. 87. 
Synonymy.—The number of known forms habitant on Tinea tinca is 
large and their relations inter se are dubious. By the separation of M. 
piriformis, Thélohan has made a decided advance in the direction of 
clearness. By its lanceolate shape, single capsule, and large capsular 
index it is distinguished clearly from MV. ellipsoides and from M. brachy- 
cystis. It is probable that some of Pfeiffer’s degenerated forms should 
receive a somewhat similar interpretation. His figures are, however, 
such that in the absence of more definite statements they can hardly be 
placed. One of them (pl. 21, fig. 3d) would seem to belong to this 
species. The others are entirely indeterminate. 
Cyst.—Thélohan (1890, p. 203) saw cysts enlarge, become submucous, 
distending the mucous membrane, which subsequently ruptured, per- 
mitting the cyst to shell out and fall into the water, where it burst 
exactly as with the subcutaneous cysts of Gasterosteus aculeatus. Cysts 
are found in the comparatively exposed parts, e. g., the subcutaneous 
and intermuscular connective tissue and in the subepithelial tissue of 
the branchi, being absent in the internal organs (air-bladder, ete.). 
Myxosporidium.2—(a) In the air bladder: Two forms occur in the 
air-bladder of the tench; the first very similar to that found in the 
1See p. 211, footnote 1, and the explanations of the plates. 
2?Thélohan, Annal. de Microgr., 1890, 11, pp. 201-2, 
