304 



H. M. WOODCOCK. 



near the anterior end. (V) liosts : Rana esculenta, K. temporaria, 

 R. trinodis (?), and Bufo viridis. (I) host, probably a leech (possibly 

 an Ixodes?^). 



The Trypanosome (fig. 57), unnamed, but perhaps a distinct species, 

 which Laveran and Mesnil (56) figure from Hyla arborea, is of interest, 

 since, while of the voluminous T. rotatorium type, it has the kineto- 

 nucleus close to the anterior end, and this occupies, in respect of its shape, 

 a position midway between the tapering and the bluntly-obtuse forms of 

 that parasite. The length of this Trypanosome is given as 75 /*, its 

 breadth 7 /x. 



Dutton and Todd (1. c.) describe two Trypanosomes, both characterised by 



Fig. 56. 



A. B. 



Fig. 56. — T. rotatorium (Mayer), a, ribbed form ; B, smooth 

 form. X 1000 (about). (After L. and M.) 



Fig. 57.— T. sp., from Hyla arborea. (After L. and M.) 



their great length, from frogs (sp. incert.) in Gambia. The authors give 

 each form provisionally a new specific name, T. mega and T. karyo- 

 zeukton respectively. Both parasites strongly resemble the fusiform 

 type of T. rotatorium (which was also encountered in the frogs of that 

 district), so much so that Laveran and Mesnil consider them to be 

 hardly specifically distinct. Although in tiiese new forms the anterior end 

 is very long and proboscis-like, these authois say that they liave observed 

 individuals of T. rotatorium with an equally thin and extended anterior 

 extremity. While the parasites are undoubtedly closely allied to that 



' Durham (I.e. [fn. 3, p. 291J) considers that an Ixodes is the Inver- 

 tebrate host of a Lankesterella (Drepanidium) of toads ; see, how- 

 ever, T. inopinatum, below. 



