191M 33 



of Xenopsylla aequisetosus and X. clieopis were duly pointed out, and 

 the receptacula seminis figured. The male was not known at that time. 



The Imperial Bureau of Entomology have since received a number 

 of specimens of both sexes of X. aequisetosus, which have been lent to 

 us for description. Both the (^ and ? of X aequisetosus, although 

 very similar to X. cheopis, its nearest ally, are easily distinguished from 

 that species by the genitalia. In X. aequisetosus the outer process, P ' 

 {rf. Fig. 1), of the organs of copulation is broader apically than that 

 of X. cheopis, being widest at the apex, and truncate. The bristles of 

 this process, about nine or ten, are rather stronger and somewhat 

 differently arranged than in X. cheopis, and the dorsal portion of the 

 process, i.e., the portion above the bristles, is so little chitinised that it 

 is quite indistinct in specimens cleai-ed and mounted in balsam, the 

 bristles in such specimens appearing to be placed along the dorsal 

 margin of the process, which is not the case. In non-mounted 

 specimens the true outline of process P ^ is more easily observed. The 

 second process, P "^ , is slightly broader than in X. cheopis, and the 

 ninth sternite (IX. st.) more strongly curved apically. 



The females of the two species are best recognised by the recepta- 

 cula seminis. In X. cheopis (Fig. 2) the head is not so broad as the 

 basal portion of the tail — the tail, moi-eover, being very long. The 

 receptaculum seminis of X. aequisetosus (Fig. 3) is much smaller, and 

 its head is broader than the tail. 



X. aequisetosus was originally described from Togoland, where it 

 was found on a Cricetomys. The specimens received by the Imperial 

 Bureaii of Entomology were obtained in Accra, Grold Coast, and at 

 Zomba, Nyasaland, on Cricttoiays cjambianus. It has also been found 

 on the Brown Eat, Mas. norvegicus, in Accra, Gold Coast. 



I. Enderleiu, Zur Kenntniss der Flohe and Sandflohe, in Zoolog. 



Jahrbtich, Abt. Syst., XIV, pp. 549-557, Text-tigs. A & B, 



Taf. 34 (1901), 

 II. Jordan and Eothschild, Eevision of the non-combed eyed 



Siphonaptera, in Parasitology, I, pp. 1-lUO, pis. I-VII, 



(1908). 

 III. Jordan and Eothschild, Katalog der Siphonapteren des Koni- 



glichen Zoologischen Museums in Berlin, in Nov. Zool., 



XVIII, pp. 57-89, Text-figs. 1-10 (1911). 



Arundel House, 



Kensington Palace Gardens, W. : 

 Januo,ry, 1917. 



