48 MISC. PUBLICATION 5 00, U. S. DEPT. OF AGRICULTURE 



Thrassis petiolatus (Baker) 



Ceratophyllus petiolatus Baker, 1903, U. S. Natl. Mus. Proc. 27: 415, pi. 18, 



figs. 7-11. 

 Thrassis petiolatus Jordan, 1933, Novitates Zool. 39: 73. 



Type host. — Lynx canadensis Kerr (Canada lynx). 



Type locality.* — Moscow, Idaho. 



Range. — Western part of the United States and Canada. 



The type host of this species is undoubtedly not a natural one, 

 as the species occurs normally on rodents. The original description 

 of it is accompanied by illustrations but is based on a single male. 



Thrassis spenceri Wagner 



Thrassis spenceri Wagner, 1936, Ztschr. f. Parasitenk. 8 : 655. 



Type host. — Mcmrrwta sp. (woodchuck) . 



Type locality —Birch Island, British Columbia. 



Range. — Known only from British Columbia. 



This species is, according to its describer, most nearly related to 

 Thrassis acamantis Rothschild, from which it differs in having 

 shorter labial palpi and in a few other characters. 



Thrassis stanfordi Wagner 



Thrassis stanfordi Wagner, 1935, Ztschr. f. Parasitenk. 8: 344, figs. 15-18. 



Cotype hosts. — Marmota far) rent ris engelhardti (Allen) and 

 M. f. nosophoraHow. (woodchucks). 



Cotype localities. — Fish Lake, Saiina. and Logan, Utah. 



Range. — Utah. 



This species belongs to a group of species in which the labial palpi 

 are very long and the parameres are rounded distally. 



The Genus Oropsylla Wagner and Ioff 



(Fig. 7, D) 



Oropsylla Wagner and Ioff, 1926, Rev. de Microbiol, et d'Epidemiol. Saratov 

 5: 86 and 120. Type, Ceratophyllus silcmtjewi Wagner (by original desig- 

 nation). 



Frontal tubercle small, either rounded or angulate apically. Forehead with 



1 complete ocular row of lateral setae ami usually with an additional in- 

 complete row. Eyes well developed, black. Labial palpus 5-s< gmented and 

 extending beyond apex of coxa I. Postantennal region of bead with but a 

 single row of lateral setae, the posterior, marginal row. Pronotal comb with 

 usual long, black spines. Femur I with several lateral setae ; coxa III with- 

 out a row or patch of spinelets on inner surface; segment I of posterior 

 tarsus not longer than II, III, and IV taken together; last segment of 

 posterior tarsus with 5 pairs of lateral, plantar bristles none of which is 

 shifted ventrally. Abdomen with few apical spines, all of which are dorsal 

 or nearly dorsal in position. Tergal plate VII without posterior, median proc- 

 ess: Female with 2 to 4 antepygidial bristles on each side of abdomen; 

 male with 2 on each sidv?, 1 of which may be very small. Female with a 

 single receptaculum seminis. In male, sternal plate VIII much reduced and 

 modified: sternal plate IX with conspicuous, inner, vertical processes and an 

 anterior, median apophysis. 



The genus Oropsylla. as here recognized, is composed of three 

 subgenera, the type subgenus Oropsylla and the subgenera Diamantits 



