THE H^MOFLAGELLATES. 287 



figui'es it does not seem quite so long] ; of tail and posterior flagellum (free 

 part) 16 /i. Habitat: cesophagus and anterior part of stomach of Box 

 boops. 



This form is manifestly closely allied to T. grobbeni. At the same time 

 it also exhibits great resemblance to Trypanoplasma borreli, in which 

 genus Leger has included it. In the writer's opinion, it appears to be, as 

 regards its morphology, intermediate between these two parasites, and it is 

 not easy to decide where to place it. The fact that the free part of the pos- 

 terior flagellum is not so long as the anterior one, the occurrence of a row of 

 spherules on that side along which runs the undulating membrane, and, 

 lastly, the fact that this form is not a haemal parasite point to its associa- 

 tion with Trypan op his. Leger is inclined to do away with this latter 

 genus altogether, but this seems premature, until the life-cycle is better 

 known. 



Genus Trypanosoiiia, Gruby, 1843. Principal synonyms^: 

 Unduliua, Lank., 1871 ; Herpetomonas, Kent, 1880 (only 

 in part, since the type sp. is H. muscEe-domesticae) ; 

 Paramoecioides, Grassi, 1881; H te m a t o m o n a s, Mitroplian, 

 1883; Trypanomonas, Danil, 1885 (for young forms). 

 There is no anterior flagelkim. The point of insertion of the 

 attached (posterior) flagellum into the body, and, consequently, 

 the commencement of the undulating membrane may be 



' The synonymy of this genus and of its different species is well discussed 

 by Lave ran and Mesnil (47, 56), and Salmon and Stiles (96), from whom most 

 of the information here given is compiled. An explanatory note may be 

 added with regard to Herpetomonas, since until recently the parasite of 

 rats (T. lewisi) was called by this name. This parasite was referred by 

 Kent (27) to his new genus Herpetomonas, founded for H. muscre- 

 domesticse (Burnett), the genus Trypanosoma being reserved for the 

 frog parasite and for Eberth's form from the coecum of birds, which Kent 

 termed T. eberthi. Later, when H. lewisi became better known, Senn 

 (100) revised the diagnostic characters of the genus. As a result, the prin- 

 cipal feature left by which to distinguish between Herpetomonas and 

 Trypanosoma was the presence in the former of a thickened external 

 border to the undulating membrane, of flagellar nature, which was supposed 

 to be absent in Trypanosoma. With Laveran and Mesnil's reinvestiga- 

 tion (45) of T. rotatorium (T. sanguinis), tliis difference was found not 

 to exist, and therefore the older name prevails. The name Herpetomonas 

 is retained for the original type (museaj-domestictp), which has no undu- 

 lating membrane. 



