OBSEIIVATIONS ON A FLA(1ELLATE OF (JEKCOMONAS. 259 



he failed to see this clearly. On this account I think it safer 

 to retain the g'enus Cercomonas for flagellates of the 

 character described in this paper, viz. flagellates with an 

 anterior blunt end from which arises a single long flagelluni 

 and a posterior tapering end also with a flngellutn, trace- 

 able over the surface of the body towards the insertion of the 

 anterior flaofelltim. This conclusion is come to bv Prowazek 

 also, who figures Cercomonas longicauda with two 

 flagella arising from the nucleus. 



The specific name of this flagellate is difficult to determine. 

 Dujardin named several species of Cercomonas, though he 

 was careful to state that he was far from regarding these as 

 true species, but as a convenient means of distinguishing the 

 forms met with in different infusions. From the figures of 

 Dujardin and Stein it is possible that the flagellate belongs 

 to the species longicauda, so that the flagellate described 

 here may be assumed to be Cercomonas longicauda 

 Dujardin. 



Keferences. 



Dujardin (1841). — ' Histoire naturelle cles Zoophytes Infusoires,' Paris. 

 Dalling-er, W. H., and Drysdale, J. — " Researches in the Life-histoiy of 



a Cercomonad, a Lesson in Biogenesis," ' Monthly Micr. Journ.,' 



vol. X, 1873. 



Davaine, C. (1875). — " Monadiens," in 'Diet. Encycloped. des Sciences 



Medic.; t. ix. 

 Kent, W. S.— ' A Manual of Infusoria,' London, 1880-82. 



Klebs, G. (1893).—'- Flagellatenstudien," ' Zeit. wiss. Zool.,' vol. Iv, 

 p. 265. 



Blochmann, F. (1895). — " Die mikroskopische Tierweltdes Susswassers," 

 Abt. I, ' Protozoa,' Hamburg. 



Stein, F. — 'Der Organismus der Infusionsthiere,' Abt. Ill, 2 Hiilfte. 



Prowazek, S. (1903). — " Flagellatenstudien," ' Arch, fiir Protisten- 

 kunde,' Bd. ii. 



Biitsohli, O.— In Bronn's ' Klassen u. Ordn. d. Tierreichs,' 1885-87. 



Dobell. C. — "The Structure and Life-Histovy of Copromonas sub- 



tilis, nov. gen., nov. sp.," 'Quart. Journ. Micr. Sci.,' vol. 52, 



1908. 



