THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 



215 



HaMtat. — Common on fins (where the spores exist in great numbers 

 in the subcutaneous tissue) of Gobio goMo L. (gudgeon); branchia) of 

 same fish, of Cyprinus carpio L. (cari)), and of Alburnus alburnus L. 



43. Myxobolus ? cf. oviforinis. 



Psorosperms of C>iprini(s carpio, Balbiani, 1883, Journ. tie Microgr., vii, pp. 199- 

 201; ib., Balbiani, 1881. Lcfous sar les Sporozoaires, pp. 128, 130, 131. 



Cyst and myxosporidium not mentioned. 



S2Jore. — Length 18 yw; breadth 13 //. 



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



The dimensions differ so markedly from those of M. oviformis that 

 on the present evidence 1 have not felt justified in fusing the 2 forms. 

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

 the same as that in iif. oviformis^ and also that " 18" may not impossibly 

 be an error for 8. M. Thelohan 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. incert. PI. 15, fig. 7. 



BiitscMi's reference to Gobio fluviatilis is certainly an error. His 

 figs. 18& and 18c (loaned him by Lieberkiihn) are respectively coi)ies 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. Blitschli's statement that — 



Concerning the subsequent fate of the spore, only two observers, Lieberkiihn and 

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

 sep.arates, the protoplasmic contents emerging as a small active amoeboid body (186, o). 



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

 mentions a '' psorosperm" from the body cavity of Gobio fluviatilis (see 

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

 the separation of the valves and the exit of the ama?boid posterior 

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

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

 branchise, with his statement that in this matter he is quoting, estab- 



