234 REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 



Eailliet (loc. cit., 1890) further says that every one up to tlie present 

 appears to be in accord as to the means of combating the disease. 

 It is, above all, expedient to collect the diseased fish and to bury them 

 at a certain depth and at a great distance from the water course. Tliis 

 is what was done on the Meuse and one has just seen that this course 

 succeeded sufficiently well. Thus at the end of some years the disease 

 appears to have left no traces. Thus Eailliet saw taken , even at Mezieres, 

 3 barbels, the smallest of which weighed 1*5 kilos or 3 pounds. 



Pfeiffer ' says that prophylaxis must obviously be directed to the 

 careful removal of all fishes dead of the disease. They should be 

 burned or buried with caustic alkali. By this means, perhaps, the 

 extermination of the barbel may yet be prevented. 



The only attempts at cure are cited by Eailliet, who says that M. 

 Ladague succeeded by opening the tumors in greatly prolonging the 

 life of the fish, and sometimes in curing it. If, on the contrary, the 

 disease is allowed to take its course the tumors increase rapidly and 

 the fish soon dies. 



52. Myxobolus ? sp. incert. PI. 26, fig. 1. 



Psorosperms of Cyprinus eryihrophUiahnus, Remak, 1852, Miiller's Arcliiv., i)p. 

 144, 149, pi. 5, fig. 9B. 



Spore. — Tailed and untailed were seen. 



Rah'tat. — From pigment follicles on wall of splenic artery of 

 Leuciscus {.Scardinius) erythroiihthalmKs L. 



RemarJis. — As the relation between this form and Chloromyocum 

 dujardini is at present doubtful, the present form is i)rovisionally left 

 separate. 



53. Myxobolus sp. incert. PI. 26, fig. 2. 



Globules of Cyprinus plioxinus Rayer, 1843, Rayer's Arcliiv. de Med. comp., i, 

 pp. 58-9, pi. 9, fig. 13. 



Cysts. — In the single specimen observed, 2 in number, yellowish 

 white, the size of a pin's head; contents, a mass of ovoid spores. Ether 

 rendered the cyst contents more transparent, ammonia more cloudy. 



Myxosporidium and spore unknown. 



Hahitat. — Encysted on left side of head of Phoxinvs phoxinus h., from 

 the Seule Eiver. Disease apparently rare. 



54. Myxobolus oblongus Gurley, 1893. PI. 26, figs. 3-6. 



(Psorosperms of Catostomus UibercnJaius (Le Sueur), Miiller, 1841, Miiller's 

 Archiv., pp. 487-90, pi. 16, figs. 7-9; ib., Miiller, 1843, Rayer's Archiv. de 

 M^d. comp., I, p. 229, pi. 9, figs. 7-9; i6., Robin, 1853, Hist. Nat. d. V^get, 

 Parasites, p. 301, pi. 14, figs. 9, 10.) 



Myxololus ohloyigus, Bull. U. S. Fish Com. lor 1891, xi, p. 414; ib. Brauu, 1894, 

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



Myxosporidium unknown. 



Cyst. — Eound or elliptic, not over 1 mm. in diameter; membrane 



'Die Protozocn als Kraulibeitscrreger, 2 cd., 1891, p. 110. 



