THE MYXOSPORIDIA, OR PS0R0SPERM8 OF FISHKS. 



215 



Habitat. — Common on tins (wliere the spores exist in great numbers 

 in the subcutaneous tissue) of Gobio r/obio L. (gudoeon); branchiie of 

 sajiie fish, of Cyprinm-i carpio L. (carp), and of Alburnns alhurnus L. 



43. Myxobolus ? cf. oviforinis. 



Psorosperms of Cyprhnts carpio, Balbiani, 1883, .lonrn. de Microgr., vri, pp. 199- 

 201 ; ib., Balbiani, 1884. Lc^f ons sur les Sporozoaires, pp. 128, 130, 131. 



Cyst and myxosporidium not mentioned. 



Spore. — Length 18 //; breadth lli //. 



Habitat. — On Cyprinus carpio L. (carp). 



The dimensions dil!er so markedly Irom those of 21. oviforniin that 

 on the present evidence I have not felt Justified in lusing the 2 forms. 

 It is, however, worthy of note that the ratio between the dimensions is 

 the same as that in ^1/. oviforinis, and also that '' 18 '' may not impossibly 

 he an error for 8, M. Thclohan writes that he has never found in the 

 carp spores measuring 18 by 12 //, and suggests that these dimensions 

 may be an error. 



44. Myxobolus sp. inceit. PI. lo, fig. 7. 



Biitschli's reference to Gobio Jiuviatilis is certainly an error. His 

 figs. 18& and 18c (loaned him by Lieberkiihn) are respectively copies of 

 Lieberkiihn's figs. 7 and 8. That they are not merely independent 

 figures of specifically identical material can be seen from the identity 

 of the figure of the ever-varying amoeboid (fig. 8, Lieberkiihn; fig. 18c, 

 Biitschli; see pi. 15, fig. 7c). The question is, moreover, additionally 

 settled by Prof. Biitschli's statement that — 



Conccruiug tlio subsequent fate of the spore, only two observers, liicbcrkiihn and 

 Balbiani, have so far expressed opinions. They agree tliat the spore-shell finally 

 separates, the protoplasm ie contents emerging as a small active amceboid body (18&, c). 



Thus the 2 figures in question were copied. Further, Lieberkiihn 

 mentions a " psorosperm" from the body cavity of Gobio Jliiriat iJ is (see 

 p. 243), and describes in detail his observations in that form upon 

 the separation of the valves and the exit of the anncboid i)osterior 

 mass. He makes no mention, however, of any forms upon the branchiiB 

 of Gobio ffxviatilis. The fact that Biitschli cites its habitat as the 

 brauchijc, with his statement that in this matter he is quoting, cstab- 



