92 



HON. N. CHARLES KOTHSCHILD — A SYNOrSIS OF 



4. Genns Pulex, L. 



1. P. irritans, L. The human flea. Occasionally found on rats. Practically 

 cosmopolitan. 



5. Genus Xenopsylla, Glink. 



The name Loemopsi/Ua, Jord. and Rothsch., was published a little later 

 than Xenopsylla, and must therefore giye way to the latter. The genus 

 includes numerous species from Africa: one of them {cJieopis, Rothsch.) is 

 now practically cosmopolitan, and another (hrasilie^isis, Baker) has been 

 introduced into South America. 



1. X. cheopis, Rothsch. In the (^ the bristles of the flap-like })rocess of 

 the clasper all slender (fig. 9). In the ? fhe narrow portion of the recepta-^ 

 culum seminis long (fig. 11). — Originally discovered in Egypt. This is the 

 common ilea of rats in the tropics. Although practically cosmopolitan, it 

 cannot apparently flourish in temperate and cold climates. 



2. X. brasiliensis, Baker { = vif/etus, Rothsch.). The bristles of the flap- 

 like process of the clasper of the S nearly all very stout, one of then> 

 elbowed (fig. 8); antepygidial bristle of male on a conical projection (fig. 8). 

 The narrow part of the receptaculum seminis of the 9 much shorter than in 

 X, elieopis, and the rounded portion larger (fig. 10). — Occurs on rats in West 

 Africa and has been introduced into Brazil. All the species of this genus 

 are closely allied, and great care must be taken in their identification. The 

 organs here figured are ])ractically constant in each species. 



