THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. Zio 
of the kidney of Tinea tinea L. (tench). He further asserts that the same 
form is found on the branchize, but as he does not figure any spores 
from the last seat it may perhaps be a question whether the branchie 
yield the present species in addition to W. piriform?s. 
In the kidney a 3-chambered pigment cyst was seen 27 yw (4/’’) 
long, the end compartments of which were occupied by pigment and the 
central one by a pyriform spore.’ The pigment-follicles of the spleen 
almost always contain untailed psorosperms in considerable numbers, 
lying without order between the pigment-holding cells. The pigment 
follicles of the kidneys always contain the same species as that found 
in the spleen and upon the gills (Remak). 
38. Myxobolus ? sp. incert. PI. 14, fig. 4. 
Psorosperms of Cyprinus tinca, Lieberkiihn, 1854, Miiller’s Archiy., pp. 6, 24, 
359, pl. 2, figs. 21-27. 
» Lieberkiihn’s description is substantially as follows: 
Cyst imbedded in cornea immediately under the inner surface. Upon slight pres- 
sure very many spores, partly with and partly without tail-like appendages, and 
whose shell was no longer smooth but wrinkled, and whose capsules were no longer 
together but occupied unusual positions, were seen. Individual shells contained 
only 1, and others no capsule. A number of free “nuclei” which had preserved the 
elub-shape of those within the spore also were seen. Finally, very small diaphanous, 
nongranular, ameebiform corpuscles occurred, which plainly, though slowly, moved 
with blunt or sharp processes. 
Habitat.—Encysted in cornea of Tinea tinca L. (tench). 
Concerning these figures, Thélohan (letter to author, 1893) says that 
they are not to be approximated to M. piriformis. Lieberkiihn’s fig. 21 
would, he says, rather suggest Chloromyxum dujardini. 
39. Myxobolus ? mugilis Perugia, 1891. Pl. 14, figs. 5, 6. 
Myzxosporidium mugilis Perugia, Boll. Scientif., Pavia, x11, pp. 23-24, plate, figs. 
7,8; ib., Weltner, 1852, Sitzungsber. Gesellsch. Naturf. Freunde Berlin, p.35. 
Myxobolus mugilis Thélohan, 1892, Bull. Soc. philomat. Paris, tv, p. 166; ib., 
Gurley, 1893, Bull. U. S. Fish Com. for 1891, x1, p. 414; ib. Braun, 1894, 
Centralbl. f. Bakt. u. Parasitenkde, xv, p. 87. 
Cyst membrane.—Having removed with care one of the cysts from 
the branchize of M. capito, Perugia observed it to consist of 3 (others 
contain 2) separated myxosporidia surrounded by a common investing 
membrane evidently derived from the branchial lamella, which latter at 
no point showed any solution of its continuity. From this he concluded 
that the cyst is a production of the host. Some eysts contain 2 or 3 
myxosporidia filled with spores, and with a residue of a very few granu- 
lations of protoplasm. 
Myxosporidium not described. 
Spore.—Free; ‘without a proper membrane” ?; length, 7. 
Habitat.—Encysted in the branchial lamelle of Mugil auratus and of 
M. capito (gray mullets). Rare; found only twice in 300 Mugils. 
' Remak here erroneously refers to his fig. 5a instead of fig. 7A. 
?From other similar expressions by the same author I interpret this to mean: ‘No 
pansporoblast membrane,” 
