THE MYXOSrOI7IDIA, OR PSOROSPERMS OF FISHES. 213 



of tlie kidney of Tinea tinea L. (teucli). He farther asserts that the same 

 form is found on the branchiae, but as lie does not figure any spores 

 from the hxst seat it may perhaps bo a question wliether the brauchite 

 yiehl the present species in addition to M. piriformis. 



In the kidney a 3-chambered pigment cyst was seen 27 /< (sV) 

 long, the end compartments of which were occupied by pigment and the 

 central one by a pyriform spore.' The piguient-follicles of the sj)leen 

 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 (liemak). 



38. Myxobolus ? sp. incert. PI. 14, fig. 4. 



Psorosperms of Cyprinns tinea, Lieberkiilin, 1854, Miiller's Archiv., pp. 6,24, 

 353, pi. 2, figs. 21-27. 



Lieberkiihu's description is substantially as follows : 



Cyst imbedded in coruea immediately under the inner surface. Upon slight pres- 

 sure very mriTiy spores, partly witli and partly without tail-like aiipendages, 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 tlie 

 club-shape of those within the spore also were seen. Finally, very small diaphanous, 

 nongranul.ar, amcebiform corpuscles occurred, which plainly, though slowly, moved 

 with blunt or sharp processes. 



Habit at. — Encysted in cornea of Tinea tinea L. (tench). 



Concerning these figures, Thelohan (letter to author, 1893) says that 

 they are not to be approximated to 31. piriformis. Lieberkiihu's fig. 21 

 would, he says, rather suggest Ghloromyxum dnjardini. 



39. Myxobolus ? mugilis Perugia, 1891. PI. 14, figs. 5, 6. 



Myxosporklinm m?((/t?js Perugia, Boll. Scientif , Pavia, xiii, pp. 23-24, plate, figs. 



7,8; iZ'.jWeltner, 1892, Sitzungsber. Gesellsch. Naturf. FreundeBerlin, p.35. 

 Myxobolus mugilis Thelohan, 1892, Bull. Soc. philomat. Paris, iv, p. 166- ib. 



Gurley, 1893, Bull. U. S. Fish Com. for 1891, xi, p. 414; ib. Brauu, 1894* 



Ceutralbl. f. Bakt. u. Parasitenkde, xv, p. 87. 



Cyst membrane. — Having removed with care one of the cysts from 

 the branchioe of M. eapito, 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 cysts 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, 7yw. 



Habitat. — Encysted in the branchial lamellae of Miujil auratus and of 

 M, eapito (gray mullets). Eare; found only twice in 300 Mugils. 



' Remak here erroneously refers to his fig. 5a instead of fig. 7A. 

 *Froui other similar expressions by the same author I interpret this to mean: "No 

 pansporoblast membrane." 



