THE MYXOSPORIDIA, OR PSOROSPERMS OF FISHES. 



221 



Spore. — Resembling Chloromijxum dujardini; 11 pi (O-OOol'") long 

 and 7 /u (0-0034'") broad. 



Habitat. — On Leuflismis {Squalius) (irislagine L. { = Cyprimis leticisais). 

 Tumors less common than on Leitciscus rutiJus. 



It seems strange that Miiller should approximate this form to the 

 "sharp corpuscles of C. rutilus,"'^ asLeuckart's figure resembles much 

 more closely the elliptic form figured by Miiller (Miiller's tigs. /, g; 

 ■pi. 28, figs. 5/, g). 



51. Myxobolus sp. incert. PI. 22, figs. 5, 6; pis. 23-2.5. 



* Non Biiiscbli. 



tLudwig's figures seem aa though they might be generalized composites based upon several of 

 Biitschlis. They may thus jierhaps be not independent figures of the spore habitant in the skin of 

 B. harhus, but have been considered to represent that form in view of its supposed identity with M. 

 miilleri. 



Synonj/niy. — Both Megnin and Ludwig, the former with doubt, the 

 latter apparently without hesitation, regard this form as identical with 

 M. miiUcri. While admitting their superior advantages (of direct 

 observation of material) I still feel con.siderable doubt as to the iden- 

 tity of these 2 forms, and have therefore provisionally classed them 

 separately, as, while I do not consider that there is sufficient ground 

 for a positive assertion of the distinctness of the two forms, there is 

 certainly sufficient to justify a hesitation as to their fusion. 



Megnin says the present species is probably the same as that described 

 by liobin and Balbiani as infesting the tench and carp. Now as to this : 

 (1) I am not aware that Kobin ever observed such a form, and (2) the 

 si)ore habitant on the tench {M. ellipnoideH) is, as shown by Thclohan,^ 

 unquestionably distinct from that habitant on the carp {M. oviformis). 



' "Bei C. IcHciscuH glidien sie f:janz don spitzuu Korpercht 

 « Aniiiil. de ^Slicrogr., 1890, ii, p. 210. 

 F 16 



do8 C. rutilua. " 



