THE myxospoe;dia, or PoOeosperms of fishes. 2G5 



Myxosporid'mm. — The largest attaining 75 /< (gV'" Lieberkiibu), tlie 

 smallest the size of a blood corpuscle; spherical or ellipsoidal, ]uore 

 rarely irregular, membraueless, containing irregularly scattered fat-like 

 globules. 



Spore formation. — Many myxosporidia appear destitute of fat gran- 

 ules, but show a large number of structureless gelatinous globules; 

 other myxosporidia shoAV partly the same globules, partly similar ones 

 of the same size containing 4 capsules whose apices are approximated. 

 Many globules show only faint indications of such capsules. Sometimes 

 2 such globules occur inclosed within a common structureless mem- 

 brane. Besides these, developed psorosperms occur, both individually 

 and in heaps, held together by a mucoid substance. 



Spore. — Sharp-contoured, subglobular, mucronate anteriorly; length 

 ad max., 8 /<; capsules 4, converging anteriorly. 



Habitat. — Free in urinary bladder of Lota lota L. (ling). Found in 

 about 20 per cent of the fishes examined. 



BemarJis. — Lieberkiihn emphasizes the striking resemblance between 

 this species and those described by Leydig from the gall-bladder of the 

 riagiostomes {Cldoromyxum leydigii and G. incisum). He notes, how- 

 ever, that C. mucronatum differs from Leydig's forms in the absence of 

 a membrane around the myxosporidium, and in the absence of the pan- 

 sporoblastic vesicles (Leydig's Tochterhlase). From later researches it 

 is easy to interpret Liebeikiihn's results in harmony with those of Ley- 

 dig, as the vesicle stage of the pansporoblast is merely a later stage of 

 the gelatinous globules of the above description (see pp. 81, 28G). 



SUBGEN. SPH.EROSPORA Th61obau, 1892. 



Etymology not given. 



Bull. Soc. pliilomat. Paris, iv, p. 175; Myxosoma et Mixosoma^, ihicl., p. 175; 

 subgen. (including Myxosoma and Mixosoma) of Chloromijxmn, Gniley, 

 1893, Bull. U. S. Fisli Com. for 1891, xi, pp. 411-412,418-419; Sphwrvsjwra 

 et Myxosoma, Braun, 1893, Centralbl. f. Baltt. n. Parasitenlcde, xiv, p. 739; 

 ib., Braun, Centralbl. f. Bakt. u. Parasiteukde, xv, p. 87. 



Definition. — Bicapsulate Chloromyxa; type Chloromyxum (S.) eleyans. 



Species. — The study which, through the kindness of Dr. Ohlmacher, 

 I was able to make of C. {S.) ohlmacluri enabled me to recognize 2 

 other species in the literature which should be referred to this sub- 

 genus. The first is Balbiani's spore of Acerina cernua, which I have 

 named Myxoholus perhttus. The median anterior and posterior mucro- 

 nate projections and the median line shown in Ball)iani's figures, can be 

 respectively interpreted only as the ends and the intervening portion 

 of the ridge. In other words, the valve-junction plane is vertical. The 

 appearances are identical with those shown by C. ohimacheri. The 

 second is Biitschli's spore of the ovary of Lota lota. Though Biitschli's 

 figures represent it as bicapsulate it should be compared with C. mucro- 

 nfituin. 



'Type ?r ;X(iS'ina <lii>-n-<Vnii. 



