THE H^MOFLAGELLATES. 283 



Section XII. Systematic Enumeration. 



The reasons for the division of the Trypanosomes into two 

 distinct and entirely independent families have been fully 

 discussed in the preceding section. Apart from the funda- 

 mental diagnostic characters^ it is quite likely that other 

 important features in which the parasites differ in the two 

 cases will become known as our knowledge of the complete 

 life-cycle increases. 



Sub-order. — Monadina. 



Family. — Trypanomorphida3, n. fam.' 



Hasmotiagellates derived from a uniflagellate^ Herpeto- 

 monadine form, in which the point of insertion of the flagellum 

 into the body has travelled backwards from the anterior end 

 for a greater or less distance, the flagellum itself having be- 

 come, concurrently, attached to the body for a portion of its 

 length by means of an undulating membrane. At present 

 only one genus can be said to be known with certainty. 



Genus Trypanomorpha, n.g. With the characters of 

 the family. The only species yet known is the type species, 

 T. uoctuse (Celli and San Felice). [Syn. Trypanosoma n. 

 (C. and S. F.), Schaud. = Halteridium n. (C. and S. F.)].^ 

 The full life-cycle of this parasite has been described above 

 (Section V). Vertebrate host : Athene noctua (Little 

 Owl); Invertebrate host : Culex pipiens. 



' It is considered best to remove Trypanomorplia, and other allied 

 Monadine forms which are true Hijemoflagellates, from the old family of the 

 Cercomonadidffi or Oicomonadacea?, in the same way that DoHein (19) 

 has separated the Heteromastigine section (his inclusive genus Trypano- 

 soma) from the Bodonidse. 



' Schaudinn places this form in the genus Trypanosoma. The writer, 

 however, inclines to the view that the type-species of that genus (T. rota- 

 torium) is a Heteromastigine form (see below, p. 288), in which case this 

 Avian parasite cannot be included therein. Moreover, it is altogether 

 uncertain whether the type-sp. of Halteridium (H. danilewskyi) 

 agrees generically with H. noctu£e. Quite possibly it does not, since, for 

 one thing, it possesses typical schizogony. Hence the writer thinks it best 

 to place H. noctuae in a distinct genus, Trypanomorpha. 



