A NEW MYXOSPOFJDIAX PARASITE. 5 



majority is found only in the connective tissues. Only a very few 

 species ever enter the muscle fibers, and even in these forms the 

 principal seat of infection is the connective tissues. The present 

 species appears, therefore, to be unique among the Myxosporidia, 

 since so far as known it develops onh^ within the muscle fibers and 

 never in the surrounding connective tissues. In this respect it re- 

 sembles the Sarcosporidia and lends additional interest to Darling's 

 theor}' that these muscle parasites are simply aberrant Cnidosporidia. 



For convenience a brief description of the genus Unicapsula 

 nov. gen. is appended : 



Spores rounded; asymmetrical, without processes of any kind, 

 only one large rounded capsule present ; valve of shell containing 

 capsule nuich larger than the other; tissue parasites, polysporous. 



BIBLIOGRAPHY. 



Keysselitz. G. 



1908. Die EntwickUmg von Myxobolus pfeifferi Th. II Tail. Archiv 

 fiir Proristenkunde. Elfter Band, 1908, pp. 276-308, Taf. XV u. 

 XVI, 7 Textfiguren. Jena. 

 Thelohan, p. 



1895. Recherches sur les Myxosporidies. Bulletin scientifique de la 

 France et de la Belgique. Vol. 26, pp. 100-394. Paris. 

 Thompson. William F. 



1916. A Note on a Sporozoan Parasite of the Halibut. Report. Com- 

 missioner of Fisheries. Province of British Columbia, 1915. pp. 

 127-129, 3 plates. Victoria. 



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