196 



ENTOMOLOGY FOR MEDICAL OFFICERS 



mesosternum to the uppermost corner of the latter. The 

 most notorious species is Xenopsylla cheopis, Rothschild, the 

 common rat-flea of the tropics. 



ant: 



an!: 



~~" .eye 

 '-max. 

 f-max.p. 



paxp. 



Fig. 77 — Xenopsylla cheopis. 



Fio. 78. — Hoplopsyllui anomal'us. 



Genus Hoplopsyllus, Baker (Fig. 78). This North- 

 American genus is distinguished from Pulex by the presence 

 of a comb of teeth on the hind edge of the pronotum. One 

 species, H. anomalus. Baker, has been found on the rat ; it is 

 distinguished by having about nine teeth in its pronotal 

 comb. 



Genus Ctenocephalus, Kolenati (Fig. 79). The common 

 cat and dog fleas, which are also found on rats and attack 

 man, are the best known species. The teeth of the head- 

 comb in these species are in a longitudinal row on the lower 

 edge of the head. They are cosmopolitan. 



a^t 



anr 



antgroove 



Fig. 79. — CtenocepJialus. 



Pig. 80 



maxfL- 



labialpri y 

 - mand/ 



■Ceratophyllvs. 



Genus Ceratophyllus, Curtis (Fig. 80). This is a very 

 large and widespread genus. There is a comb on the 

 pronotum, but not on the head, and there are three ante- 

 pygidial bristles on each side. C. fasciatus, Bosc a flea 

 commonly found on rats in Europe, has eighteen to 'twenty 

 teeth in the pronotal comb. 



