256 REPORT OF THE COMMISSIONER OP PISH AND FISHERIES. 



80. Myxobolus psorospermicus Tli*')lohan, 1892. PI. 34. 



(Psorospermsof Fcvca Jluviatilis, Biitsclili, 1882, Broiin's Thier-Reich, i, pi. 38, 

 lig. IG; ib., Balbiani, 1883, Joiirn. do Microgr., vii, pp. 201, 203, iig. 42; 

 psorospermsof /^.sox" lucius,ih\d.,-^\^. 201-2, fig. 41; ih., Balbiani, 1884. Lc^ous 

 sur les Sporozoaires, p. 132, fig. 37; psorospenus of Perca flur'tuliliH, ibid., 

 p. 133, fig. 38; ib., Lankestor,1885, Ency. Britan.,9 ed., xix, p. 855, iig. xvii, 

 43, 44; ib., Tii^lohan, 1889, Compt. Keud. Acad. Sci. Paris, cix, p. 604; ib., 

 Thdlohau, 1890, Annal. do Microgr., II, pp. 202, 207, 211, figs. 5-7; ib., Th6- 

 lolian, 1890, Compt. Eoud. Lebdom. Soc. Biol. Paris, ii, p. 604 ; tailed pso- 

 ros]ierms of pike, ibid.; -paoTosirnvnisof Perca fluviatilis, Pfeitler, 1890, Die 

 Protozoeu als Kraukheitserreger, 1 ed., p. 43; ib., Pfeifter, 1891, ibid., 2 ed., 

 p. 130.) 



JTcinivguna psorospermica, ' Bull. Soc. pbilomat. Paris, iv, pp. 167, 176. 



Mijxobohia psorospermica Gnrley, 1893, Bull. U. S. Fish Com. for 1891, xi, p. 418. 



Hctincnin/a psorospermica Braun, 1893, Ceutralbl. Bakt. u. Parasiteukde, XIV, 

 p. 739. 



Myxobolus psorospermica, Brauu, 1894, Ceutralbl. Bakt. u. Para8iteukde,XV, 

 p. 87. 



Cyst and myxosporidium not described. 



Spore. — Anterior extremity obtu.se; length, 35 to 40 ;< (Tlielolian, 

 1892; 30 /f, Balbiani for spore of Lucius; 30 //, Thelolian, 1890, for spore 

 of Ferca) ; breadth, 4 /x (Th^lohan, 1890). Tail curved close against ttie 

 body during develoiiment, becoming straight only after the rupture of 

 the pansporoblast membrane; caudal iuflex, 1. Capsules, 6 to 8 /< in 

 length. Maximum number of nuclei, 3; vacuole present (Th(!Iohan, 

 1890). 



Habitat. — Branchiae of Lucius lucius L. (pike) and of Perca Jluviatilis 

 (yellow perch). 



ReynarJcs. — In view of Th(elohan's positive statement as to the identity 

 of the forms habitant on the branchiie of 7v. lucius aiul F.JJuviafiUs, I 

 believe we are justified in referring all the forms fignred to one siiecies, 

 although fig. 34 (pi. 4) differs somewhat from the rest. 



81. Myxobolus kolesnikovi Gurky, 1893. PI. 35. 



(Psorosperms of Coregonvs, Kolesiiikoff, 1886, Vet. Vestiiik Kbarkoft', v, pp. 



242-248, plate, figs. 1-3.) 

 Myxobolus lot esriikovi of Coregonus fera [error],- Bull.U. S. Fish Com. lor 1891, 



XI, p. 417. 



Cyst. — Numerous, sometimes as many as 80, length 10 to 30 mm., 

 breadth 7 to 20 mm., spherical or oval, bean-shaped, yellowish-white, 

 surface of cyst-wall smooth and shining, membrane of the thickness of 

 a cigarette paper, rupturing by the slightest pressure of the forceps. 

 Contents thick, yellowish-white, creamy, consisting of spores and an 

 oily substance. 



' "One finds on the branchiae of the pike and of the perch a myxosporidian abso- 

 lutely identical in the two cases and which it is certaiuly necessary to consider as 

 constituting but a siugle species" (Th61ohan.) 



The words " Psorospermies do J. Miiller" were evidently attached to this species 

 inadvertently. Miillor knew no species on the branchiai of L, lucius. In this fish 

 he observed them only in the orbit. 



' Kolesuikort' does uot mention any species. 



