ORDER CERCOMONADIDM 



343 



Genus Heteromita Dujardin, 1841. 

 Bodonidae round or oval, with two flagella, one at each pole. 



Heteromita zeylanica Castellan! and Chalmers, 1910. 



This flagellate is elongated, 8 to 15 in length by 3 to 4 yu. in breadth, with 

 single flagellum at each pole, and a nucleus fairly rich in chromatin. No 

 undulating membrane or pulsating vacuole, but with chromidia in the cyto- 

 plasm. It is not cultivable. This flagellate we classify provisionally under 

 the genus Heteromita. It was found in the stools of persons suffering from 

 ankylostomiasis in Ceylon. 



ORDER CERCOMONADIDM Saville Kent, 1880, emendavit Biitschli. 



Definition.— Monozoa with elongate or oval forms, possessing 

 one free anterior flagellum and one trailing flagellum. 



Type Genus. — Cercomonas Dujardin, 1841, emendavit Wenyon, 

 1910. 



Remarks. — It appears to us that this is the only genus which 

 can be classified in this family at the present moment. 



Genus Cercomonas Dujardin, 1841, emendavit Wenyon, 1910. 



Synonyms. — Heteromita Dujardin, 1841, fro parte nec Cercomonas 

 Davaine, i860, nec Oicomonas Saville Kent, 1880. 



Definition. — Cercomonadidae, pear-shaped, with a protokaryon 

 type of nucleus situate near the flagellar extremity, with a basal 

 granule or blepharoplast from which a sort of rhizoplast may run 

 to the margin of the cytoplasm, at which it divides into the two 

 flagella, one of which is anterior, while the other is posterior and 

 closely attached to one side of the body, at the posterior end of 

 which it becomes free. 



Type Species. — ^The type species of the properly defined family 

 is certainly Cercomonas longicauda Dujardin, 1841, emendavit 

 Wenyon, 1910, even though the first species in Dujardin's descrip- 

 tion is C. detracta, because this latter has never again been described, 

 and has therefore never been examined by modern methods. 



Certainly Dujardin's genus Heteromita agrees in description and 

 illustration with many of the f eatures_of C . longicauda, and therefore 

 we consider it to be a synonym. 



There are a number of species described by Dujardin, but until 

 they have been examined by modern methods it is impossible to 

 define them. They are all free-living forms. 



Cercomonas longicauda Dujardin, 1841, emendavit Wenyon, 1910. 



Synonyms. — Cercomonas parva Hartmann and Chagas, 1910. 



Definition.- — Cercomonas elongate 8-15 x 3-4 microns, with very 

 marked long posterior flagellum. 



History. — ^This flagellate was first discovered by Dujardin in 

 1841 in an old infusion, and was next described by Wenyon in 1910, 

 being found in cultures made from human faeces. In the same year 



