THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 243 



Spore. — xllways 2, oval, with 2 capsules situated " at the superior 

 border in the transverse diameter." Perugia did not see the extrusion 

 of the filaments under the action of reagents. He adds that he has 

 convinced himself of the accuracy of Tlielohan's opinion as to tlie 

 vacuolic nature of Biitschli's ''nucleus" and also of that of Th^lohan's 

 observations upon the nuclei of the spore. 



Hah i fat. — (xall -bladder of MerluGius merlucius {= esculentus, = vul- 

 garis), hake, collected August 13, 1890. 



EemarJcs (see also ]). 275). — This is a rather peculiar species, and the 

 generic reference is provisional. As indicated elsewhere, gall-.bladder 

 species of Myxoholus are so rare that this habitat is a caution-mark as 

 to the generic reference of imperfectly described forms. The present 

 generic reference is made provisionally and very doubtfully upon Peru- 

 gia's assertion of the presence of an iodinophile vacuole. Finally, 

 attention may be directed to Perugia's figure 9 (pi. 29, tig. 2), which 

 differs entirely from the others. 



65. Myxobolus ? sp. incert. 



Psorosperms of Gohio Jluviatilis Lieberkiiliii, Miillor's Arcliiv., pp. 353-4; ib., 

 Lieberkiilin, 18.54, Bull. Acad. Roy. Belg., xxi, pt. 2, pp. 21-2; ? myxo- 

 sporidian of kiduey of G. fltiviatilii Thelohan, 1890, Aunal. de Microgr., 

 II, p. 198; ib., of Gobius [error] Pfeiffer, 1890, Die Protozoen als Krank- 

 heitserreger, 1 ed., p. 49; ib., Pfeiffer, 1891, ibid, 2 ed., p. 134. 



Cyst. — Nearly spherical, about 0.22 mm. in diameter; contents, "pso- 

 rosperms," empty shells of the same, " free nuclei " of the same, and 

 amoeboid bodies with amoeboid movements. 



Mi/.vosporidiiini.^-The above and below mentioned amoeboid bodies 

 in all probability represent the earliest stages. 



Spore. — Un tailed, Lieberkiihn repeatedly saw spores contract to an 

 hour-glass shape and extrude an amoeboid body, which formed blunt 

 processes, and moved slowly over the field, the movements continuing 

 for a long time 5 amoeboid bodies diaphanous, destitute of granules 

 and of apparent structure, usually invisible within the .spore, but some- 

 times plainly seen; size, that of a colorless blood corpuscle. 



Habitat. — In the kidney and encysted in body cavity between the 

 kidney and the air-bladder of Gohio gohio L. 



Rcmarlcs. — The habitat and the " encysted " condition of this form 

 imply Myxoholus aflBnities. 



66. Myxobokis ? sp. incert. 



Psorosperms of Percrt, ^Hrm/j/(\<(, Miiller, 1841, pp. 481, 490; t&. Robin, 1853, Hist. 

 Nat. des V^g6t. Parasites, p. 296; ib. Lieberlviihn, 1854, Miiller's Archiv., 

 p. 365; ib. Bessels, 1867, Tagebl. d. 41 Versamml. d. deutsoh, Naturf. u. 

 Aerzte, pp. 71-72. 



Cyst mentioned but not described by Lieberkiihn; myxosporidium 

 unknown. 



Spore. — Untailed. Bessels observed the extrusion of the filaments 

 as a result of 8 hours' immersion in glycerin. 



Mabitat. — In May and June encysted in the skin of Ferca Jluviatilis 



