THE MYXOSPOKIDIA, OR PSOROSPERMS OF FISHES. 195 



ransporoblast spherical, average diameter 15 to 18 /^; menibraue 

 thin, transparent, containing, besides fully developed spores, sporo- 

 blasts in diiterent stages of development, some of them measuring 2-5 

 to 3 yu, and containing one or several colored granules representing 



nuclei. 



^S^jom— Ovoid, resembling that of Ghigca anomala; length, 3 /<; 

 breadth, 1-5 to 2 //; a single capsule with a filament is present j large 

 extremity showing a mass refractory to staining iiuids, the remainder 

 of the spore cavity containing sporoplasm, and a body apparently repre- 

 senting the nuclear element of the spore, staining strongly with reagents, 

 and in certain cases decomposable into separate granules whose num- 

 ber never exceeds 4. 



jff«&ito<.— Muscles of CoUns scorpio (sculpiu); position interfibrillar. 



Effects.— Diseased mass forming small white streaks of an average 

 size of 5 to 6 mm. by 3 mm., consisting of spores. The fibers affected 

 increase in bulk; they are filled with the pansporoblasts disposed 

 without regular order between the fibrillne, which latter become sepa- 

 rated and distorted, without, however, presenting any alteration of 

 structure or diminution in the clearness of their tranverse striation. 



III. THELOHANIA Henneguy, 1892. 



Etymology : Th^lolian. 



In Thelohaii, Bull. Soc. philoinat. Paris, iv, p. 174, footnote; t&. Henneguy, in 

 Henneguy and Theloban, Annal. de Microgr., Paris, 1892, i\', p. 639; ib. 

 Gurley, 1893, Bull. U. S. Fisli Com. for 1891, xi, pp. 409-410; ib. Braun, 

 1893, Ceutralbl. f. Bakt. u. Parasiteukde, xiv, pp. 739-740 ; ib. Braun, 1894, 

 Centralbl. f. Bakt. u. Parasiteukde, xv, p. 86. 



Befinition^ (provisional as regards negative characters).— (^twf/ei^fe 

 destitute of a myxosporidium and in which the pansporoblast pro- 

 duces constantly 8 spores; pansporoblast membrane subpersistent as 

 an octosporophorous vesicle; type T. giardi? 



Henneguy and Thelohan remark that in this genus the spores unques- 

 tionably approximate those of Glugea anomala and those of PleistopJiora. 

 The number of spores formed in the pansporoblast and the absence of 

 a myxosporidium differentiate Thelohania from Glugea. On the con- 

 trary, the last character and the subpersistence of the pansporoblast 

 membrane as a sporophorous vesicle, approximate it to Fleistopliora. 



1 Henneguy's definition is : 



" Spores pyriform, with one polar capsule at the small extremity and, at the opposite 

 extremity, a clear vacuole with contents not colorable by iodine. Sporoblasts pro- 

 ducing only 8 spores surrounded by an envelope persisting after the formation of 

 these last; no plasmic mass, properly speaking." 



As constituted by Henneguy the genus included only 3 species, T. octospora, T. giardi 

 and T. contejeani. 



sType proposed by the author in Bull. U. S. Fisli Com. for 1891 (1893), xj, p. 410. 



