14 Fleas oj Eastern United States 



HOPLOPSYLLUS BAKER 

 Hoplopsyllus Baker, 1905, Proc. United States Nat. Mus., 29: 128. 

 Genotype: Pulex anomalus Baker 



Eye bristle not placed higher than the eye itself. Genal 

 ctenidium absent. Pronotal ctenidium present. Mesosternite 

 divided by a distinct vertical rodlike sclerotization. 



This genus is represented in the East by two closely related 

 species which are parasitic chiefly on rabbits and hares. The 

 females of these two species are separated by characters which 

 do not lend themselves readily to arrangement in key form. The 

 males may be differentiated by the following key: 



Key to the Eastern Species of Hoplopsyllus (males only) 



Posterior process of the movable finger not more than twice as long as 

 the anterior process H. affinis 



Posterior process of the movable finger more than twice as long as the 

 anterior process H. lynx 



Hoplopsyllus affinis (Baker) 



(Plate IV, figs. 12, 14, 15) 



1904 Pulex affinis Baker, Proc. United States Nat. Mus., 27:382. 



1905 Hoplopsyllus affinis Baker, Proc. United States Nat. Mus., 27:130. 



Male. Preantennal region of the head with only two bristles, 

 one of which is located near the eye, the other at the base of the 

 maxillary palpus. First segment of the antenna with a number 

 of slender bristles along the posterior edge and apically. Sec- 

 ond antennal segment with four or five long bristles. Post- 

 antennal region of the head with but two bristles in addition 

 to the marginal row of four or five bristles. Near the third 

 antennal segment is a group of about seven setae. Pronotal 

 ctenidium consisting of eight or nine spines on a side. Pro- 

 notum, meso-, and metanotum each armed with a single row 

 of bristles. Modified segments: Clasper with two processes, 

 the anterior broad and lobular, armed with about eight stout 

 bristles; the other much more slender with a broad black tooth 

 apically, usually less than one and one-half times as long as the 

 anterior process. Manubrium small and broad, curved upward. 

 Penis long, slender, and bladelike; spring long, but not complet- 

 ing a turn in the specimens examined. For further details con- 

 cerning the structure of the male genitalia, see Plate IV, fig. 14. 



Female. Chaetotaxy of the head (Plate IV, fig. 12) and gen- 



