102 



Psyche 



[August 



the females of the various species of Polyplax only by its extremely 

 broad head and the stout spine at the base of each antenna. The 

 female in general resembles the male, but has the antennae simple, 

 that is without a preaxial process on the third segment, and lacks 

 the emargination of the posterior margin of the second abdominal 

 tergite. 



Hsemodipsus ventricosus Denny. 



Numerous specimens from skins of Lepus californiciis (Areata, 

 Humboldt Co., Calif.) and Lepvs californicus 

 deserticola (Ehrenberg, Ariz.). The male, which 

 has never been adequately described, is similar 

 to the female except for its much smaller size. 

 The genitalia are very large and conspicuous, the 

 basal plate being long and relatively slender, the 

 parameres about half as long as the basal plate 

 and very broad and heavy. Penis very small and 

 inconspicuous. 



It should be noted that the sternal plate is not 

 as regularly hexagonal as it is figured in "Ano- 

 plura and Mallophaga of North American Mam- 

 mals," the posterior margin being longer than the 

 anterior and closer to the lateral angles. 



Fahrenholzia pinnata Kellogg & Ferris. 



From Perodipus sp? (Coulterville, Mariposa 

 Co., Calif.) and skins of Dipodomys merriami 

 ssp. (Independence, Inyo Co., Calif.), Dipo- 

 domys deserti (Mecca, Riverside Co., Calif.), 

 Microdipodops polionotus (Benton, Mono Co., 

 Calif.) and Perognathus parvus olivaceous 

 (Pine Forest Mts., Nev.). 



Host of the type, Dipodomys californicus. 



Fig. 3. Hcemodip- 

 sus ventricsus (Den- 

 ny) ; genitalia of 

 male. 



Fahrenholzia tribulosa sp. no v. 



From Perognathus californicus ssp.'^ (Pleasant 



Valley, Mariposa Co., Cahf.), and Perognathus 



formosus (Victorville, Calif.). This is a very distinct form that 



differs markedly from F. pinnata in the character of the male 



