130 THE CANADIAN ENTOMOLOGIST. 



PRELIMINARY STUDIES IN SIPHONAPTERA.— IV. 



BY CARL F. BAKER, FORT COLLINS, COLO. 



Genus Ptilex (Division 11.^ continued.) 

 Table of Species of Group 2. 



A. Abdominal segments each with three dorsal rows of bristles; 



whole insect very heavily spined and bristled ; antennal groove 

 in middle of head ; bristles on joint 2 of antennae longer than 

 joint 3 ; maxillary palpi in female with joint 2 four-fifths of 4, 

 and 3 two-Uiirds of 4 ; labial palpi reaching to one-third of 

 anterior femora ; pronotal comb of 20 spines ; in anterior 

 tarsi joint 3 two-thirds of 2 and shorter than i, 5 twice 4 

 and less than i and 2 together ; in middle tarsi joint 2 slightly 

 shorter than i and longer than 5, 5 twice 4, and i long as 

 3 and 4 together; in posterior tarsi joint i long as 2 and 3 

 together, 5 one-half of i and much longer than 3, 2 about as 

 long as 3 and 4 together, and less than 4 and 5 together; hind 

 femora with a row of bristles on the side ; leg spines long, apical 

 spines on second joint of hind tarsi longer than joints 3 and 4 

  together; colour, light brown ; length, 2-3 mm. .hirsutus, n. sp. 

 AA. Abdominal segments each with one dorsal row of bristles ; an- 

 tennal groove in middle of head ; maxillary palpi in female with 

 joint 3 three-fourths of 4 ; labial palpi reaching to one third of 

 anterior femora ; spines on legs medium ; apical spines on joint 

 2 of hind tarsi longer than joints 3 and 4 together ; in middle 

 tarsi joint 5 longer than twice 4, i shorter than 3 and 4 



together ; hind femora with a row of bristles on side D. 



AAA. Abdominal segments each with two dorsal rows of bristles ; in 

 middle tarsi joint i equals 2 ; bristles on joint 2 of antennce 

 long as joint 3 ; spines on legs medium B. 



B. Apical spines on joint 2 of hind tarsi long as joints 3 and 4 



together ; antennal groove in middle of head ; maxillary palpi 

 in female with joint 2 three-fourths of 4, and 3 two-thirds of 4; 



*F. pencilliger, Grube, and P. iiielallesceiis, Kol., should have been mentioned as 

 belonging to this division. The very insufficient descriptions render their location 

 impossible. The former was described from various Musielidcc, and the latter from 

 Xanfharpyia (Vgyptiaca. P. eihidnu\ Denny, described from Echidna hystrix (Van 

 Diemen's Land), should likewise have been mentioned in connection with 

 Division I. These names doubtless represent good species, and it is to be hoped that 

 collectors living within the range of these animals will take pains to obtain good series 

 of the fleas infesting them. 



