Family Hystrichopsyllidae Tiraboschi 101 



First genal spine much shorter and broader than the other. 

 Postantennal region of the head with three oblique rows of 

 bristles, the first row consisting of five or six, the second of 

 seven or eight, and the third of about seven. Posterior to the 

 antenna along the antennal groove are numerous long hairlike 

 setae (Plate XXV, fig. 131) . Pronotum with two rows of 

 bristles, and a ctenidium of about ten or eleven spines on a 

 side. Meso- and metanotum each with numerous irregularly 

 arranged bristles in addition to the marginal row. Each ab- 

 dominal tergite armed with three rows of bristles; in addition, 

 the anterior tergites may be armed with one to several short, 

 stout dorsal teeth on a side. Three long, antepygidial bristles 

 present on a side. Head of the receptaculum seminis broad and 

 long, more or less oval in shape. Sternite VII without a sinus, 

 the posterior margin truncate. For further details concerning 

 the female genitalia, see Plate XXV, fig. 129, which was drawn 

 from a specimen taken off "Tamias striatus" at Branchtown, 

 Ontario, Canada, (G. F. Dippie) , loaned through the courtesy 

 of Dr. Karl Jordan. 



Male. In the absence of a specimen for study, the following 

 description and the accompanying illustration are taken from 

 Rothschild's original description. Frontal and dorsal portions 

 of the head covered with numerous hairlike setae. First four 

 abdominal tergites with two or three teeth on a side dorsally. 

 Sternites with hairlike setae ventrally, the hairy area extending 

 basally beyond the middle of each segment. Modified segments: 

 Process of the clasper tongue-shaped with numerous setae on 

 the margins. Movable finger more or less boot-shaped with the 

 apex truncate, its ventro-distal margin compressed carniform 

 and clothed with setae. Manubrium long and slender, curved 

 distally. Sternite IX boomerang-shaped, bearing numerous 

 setae of various sizes ventrally, the more apical ones spiniform. 

 For further details concerning the structure of the male geni- 

 talia, see Plate XXV, fig. 127. 



Eastern hosts. Chipmunk (Tamias striatus lysteri 

 (Richardson) ) , "Cottontail Rabbit," Red Squirrel (Sciurus 

 hudsonicus loquax Bangs) , Weasel (Mustela noveboracensis 

 noveboracensis (Emmons) ) . 



Eastern localities. Massachusetts, New York, Michigan, 

 (Canada) . 



Type material. Several specimens from Branchtown, On- 

 tario, Canada, on "Tamias striatus" in the N. C. Rothschild 

 Collection (British Museum) . 



