206 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



Fam. MYX0B0LIDJ3 Gmloy, 1893. 



(Mijxosporidieoe^ Perugia, 1891, Boll. Scientif., Pavia, xin, p. 28; Myxobo- 

 Ices Tiielolian, 1892, Bull. Soc. plulomut. Paris, iv, pp. 173, 176.) 



MyxoboUdiv, Bull. U. S. Fish Com. for 1891, xi, p. 413; Myobolca [TlnH.] 

 Brauu, 1893, Ceutralbl. f. Bakt. u. Parasiteukde, xiv, p. 739; ib., Braun, 

 1894, Centralbl. f. Bakt. u. Parasitenkdo, xv, p, 86. 



Definition. — Fluvnocystes, wLose spores are destitute of aiitero-pos- 

 terior, but possess bilateral, syinnietry;^ capsules 2, iu 1 groui) at the 

 anterior end; a bivalve shell, the plaue of junction of whose valves is 

 parallel to the l()ni>itudiual i)huie; an iodinophile vacuole; type (and 

 only) genus Jllyxoljolus. 



IV. MYXOBOLUS Biitsclili, 1882. 

 Etymology uot giveu. 



Bronu's Tbior-lteicb, i, pi. 38, figs. 6-10, aud of subsequent authors; j7).,Lauk- 

 ester, 1885, Eneycl. Britan., 9 ed., xix, p. 855; ib., Thdlohan, 1890, Auual. 

 de Microgr., ii, p. 213; Myxosporidium^ Perugia, 1891, Boll. Scieutif., Pavia, 

 XIII, p. 23; ih., Weltner, 1892, Sitzgsber. Gesellsch. Naturf. Frounde 

 Berlin, p. 34; MyxosporUlium, ibid., p. 35; Myxobolus et Hennefjuya* Th61o- 

 hau, 1892, Bull. Soc. philomat. Paris, IV, pp. 176, 177; Myxobolus, Perrier, 

 1893, Traitd de Zool., p. 460; ih., Gurley, 1893, Bull. U. S. Fish Com. for 

 1891, XI, pp. 411-13; i&., Braun, 1894, Centralbl. f. Bakt. u. Parasiteukde, 

 XV, p. 86. 



Definition. — Characters, those of the family. 



Hennegnyais separated from Myxohohis by only 2 characters, viz, (1st) 

 capsules constantly 2, and (2d) the presence of a tail. Tnasmnch, how- 

 ever, as all the numerous typical Myxoholus species have 2 capsules, and 

 only 2 species are known to deviate in this respect in the direction of 

 capsule-rednction, the typical number of capsules in Myxoholus is 2; so 

 that the 2 ditferential characters in reality reduce to the siugle one of 

 the presence of a tail. This in itself is not sufficient to warrant a 

 generic separation, especially in view of the entire accord betweeji the 

 tailed and untailed forms in regard to symmetr^^, similar position of the 

 valves, exactly similar vacuole, nuclei, etc. Besides, it may be noted 

 that it has been several times asserted that tailed and untailed forms 

 occur iu the same cyst. Thus Miiller,^ Lieberkiilm,'^ and Biitsclili'' 



^ Myxosporidiam Perugia (synonym for Myxobolus BiitscMi?) proposed as type 

 of Fam. Myxospondiuo} Perugia, by the author in Bull. U. S. Fish Com. for 1891, 

 XI, p. 413. 



^Except species which have suifored reduction of characters {Myxobolus iDiicapsn- 

 latus, M. inrifovnus, M. incqualis). Porliaps M. sirongyhirus should be added. 



■^ Myxosporidium merhicii proposed by the author (Bull. U. S. Fish Com. for 1891 

 (1893), XI, p. 413) as the type species. The name Myxosporidium, having been pro- 

 posed as a new name for a genus formed by the fusion of several good genera each 

 of which already possessed a name in good standing, must be suppressed. 



* ITenncynya psorospennica proposed as the generic type by the author (Bull. U. 

 S. Fish Com. for 1891 (1893), xi, p. 413). 



''See Myxobnhis sp. 01. ]>. 210. 



"Miilltr's Anhiv., 18JI,p. 6; M(5iu. C'our. et Mom. Sav. Tltraug. Acad. Roy. Belg., 

 185.-1, XXVI, p. 37. 



■ Bionn's Tiiicr-Koieh, 1882, I, p. 5!I7. This is i)robal)ly only an opinion as to the 

 consensus, and not an independent one. 



