4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I23 



Female. — Bursa copulatrix (fig. 9, B.C.) well sclerotized, sinuate 

 and narrow, with expanded bulblike apex at point of juncture with 

 spermathecal duct (SP.D). Body of spermatheca ovate to subovate, 

 tail usually joining head with no definite line of demarcation. Eighth 

 tergum with patch of extremely small mesal hairs proximal to ventral 

 anal lobe. Eighth sternum reduced, poorly sclerotized and with no 

 bristles. Ninth sternum much reduced, with no bristles or hairs. 



Genotype. — Ctenopsyllus hesperomys Baker, 1904. 



Remarks. — Peromyscopsylla can be separated from Leptopsylla 

 (sensu stricto) by the fact that the genal comb consists of two hori- 

 zontal subparallel spines, not three, four, or six spines; and by the 

 absence of a distinct trabecula centralis. Dr. Karl Jordan (in litt.) has 

 pointed out an additional fundamental feature: in Peromyscopsylla, 

 the base of the forecoxa extends upward and covers the anterior end 

 of the prosternum. In Leptopsylla (sensu stricto) the anterior end of 

 the prosternum is above the base of the coxa (Smit, 1951), while the 

 trabecula centralis is prominent as a dark tuber at upper margin of 

 antennal groove. 



Peromyscopsylla and Paractenopsyllus Wagner, 1938, are the only 

 genera in the subfamily Leptopsyllinae that possess a genal comb of 

 two spines. In the latter genus, however, the spines of the comb are 

 vertical in position, not horizontal, and the spines are pointed, not 

 blunt. Paractenopsyllus nevertheless agrees with Peromyscopsylla in 

 the absence of the trabecula centralis, and in the manner of attachment 

 of the procoxa to the anterior end of the prosternum. There are geni- 

 talic differences beyond the scope of this paper. 



The characters of the subfamily Leptopsyllinae have been discussed 

 by Traub (1952), who lists reasons as to why this group of fleas 

 belongs in the Ceratophyllidae and not the Hystrichopsyllidae. Affini- 

 ties with the Amphipsyllinae are therein pointed out. 



KEY TO MALES OF GENUS PEROMYSCOPSYLLA 



1. No spiniforms at frontodorsal angle of head (fig. 91 ) 2 



Two or more spiniforms at frontodorsal angle of head (fig. i) 3 



2. Second antennal segment with extremely short bristles (not reach- 



ing past second segment of club) ; crochets duckbill-shaped (fig. 

 115, CR.) ; well-developed proximal spur (fig. 115, P.S.) ; eighth 

 sternum conical, bearing three apical and five or six subapical 



bristles (fig. 99) himalaica (Rothschild), p. 62 



Second antennal segment with apical bristles reaching end of club ; 

 crochets very large, slipper-shaped (fig. 121, CR.) ; no proximal 

 spur; eighth sternum apically long and narrow, with ventromar- 

 ginal row of bristles (fig. 97) tikhomirovae (loff), p. 60 



