DESCRIPTIONS AND DETERMINATIONS OF SPECIES 



19 



us are of a species of Hoplopleura, we are assuming that Haematopinus 

 erraticus is a species of Hoplopleura, and are therefore assigning it pro- 

 visionally to this genus. Osborn records the species from a gull (beyond 

 a doubt a case of straggling) and also from Arvicola sp. (= Microtus 

 sp.), Tamias striatus, and Sciuropterus volucella. We have at hand spe- 

 cimens from hosts very closely related to these, and find that our ma- 

 terial includes three species of the genus Hoplopleura. It being impos- 

 sible to decide which, if any, of these species is H. erratica we are de- 

 scribing all of them as new in the hope that the matter may be cleared up 

 later. 



Hoplopleura arboricola n. sp. 



Plate IV, fig. 4 ; plate VI, fig. 8 ; text figs. 6 and 7. 



Numerous males and females from Eutamias hindsi (Inverness, 

 Marin county, Calif.) ; Eutamias townsendi ocrogenys (Freestone and 

 Cazadero, Sonoma county, Calif.) ; Eutamias sp. (Covelo, Calif.) ; Eu- 

 tamias sp. (South Yolla Bolly Mt., Tehama county, Calif.; Sanhedrin 



Fig. 6. — Hoplopleura arboricola n. sp. ; head and pleural plates of female from 

 Eutamias townsendi ocrogenys. 



