402 THE ZOOLOGIST. 



slightly incurved. First segment of maxillary palpus longer 

 than the second. Fore femur with several small lateral bristles 

 on outside, hind femur without a subventral row of bristles. 

 Mid and hind tibias with two to four single dorsal bristles in 

 between the postmedian and subapical dorsal pairs. Bristles 

 of tarsi short, fifth segment with the first pair of plantar bristles 

 moved on to the ventral surface. In the male the eighth 

 sternite is large ; the movable process of the clasper armed 

 with strong spiniform bristles ; clasper without a bristle at the 

 insertion of the movable process ; ventral arm of ninth sternite 

 without sinus. In the female the eighth tergite with an oblique 

 vertical row of bristles on- the side, proximally to the row some 

 smaller bristles, and at the apex two bristles (rarely one), below 

 which there is a small bristle on the inside ; duct of recepta- 

 culum seminis short, head of same at least as long as the tail. 



Genotype shelkovnikovi, Wagn. (1909). 



Not any single one of the above-mentioned characters is 

 restricted to Amphipsylla. The genus Ceratophyllus contains 

 several species with reduced eyes or with one ventral and four 

 lateral pairs of plantar bristles on the fifth tarsal segment, or 

 with short bristles to the second antennal segment, &c, but 

 a combination of all these characters is only met with in 

 Amphipsylla. 



Whereas the males of Amphipsylla are easily distinguished 

 from one another by differences in the modified abdominal 

 segments, the females are exceedingly difficult to separate, at 

 any rate in some of the species. The number of bristles is not 

 reliable, as Wagner has already pointed out, and even the 

 posterior abdominal segments are in some cases of no assistance. 

 For these reasons, therefore, it will be a difficult matter to 

 identify those species which have been described from females 

 only, viz. shelkovnikovi, sibirica, rossica, and thoracicus. 



The males, apart from the genitalia, are likewise so much 

 alike that the description of one species fits in almost every 

 detail all the other species. 



The seventh sternite of the female is truncate, rotundate, or 

 slightly incurved in shelkovnikovi, thoracicus, dcea, pollionis, and 

 casis ; while this segment is obliquely sinuate with the upper 

 angle distinctly produced as a lobe in the two new species here 



