NO. 



4 FLEA GENUS PEROMYSCOPSYLLA— JOHNSON AND TRAUB 29 



111-113, 1940.— J ELLISON and Good, U. S. Publ. Health Serv., Nat. Inst. 

 Health Bull. 178, p. 123, 1942. 



Head.— As in hesperomys except : only two rather slender spini- 

 form bristles at anterodorsal angle; genal lobe not extending poste- 

 riorly one-half length of lower genal spine ; second segment of antenna 

 with fringe of bristles not reaching one-half length of club in male ; 

 three-fourths length in female. 



r/iom.1'.— Essentially as in hesperomys except no erect bristles 

 dor sally on mesonotum. 



Abdomen.— UsuaWy with three antepygidial bristles in both sexes 

 (female may have four). 



Male. — Eighth tergum with two rows of large bristles mediolater- 

 ally, first of one or two bristles, second of three. Eighth sternum (fig. 

 52) with conspicuous broad deep sinus; upper lobe subtruncate, with 

 three long marginal bristles ; lower lobe acute, with one shorter sub- 

 marginal bristle; membranous process (M.P.) reduced to narrow 

 vertical band. Immovable process of clasper (fig. 49, P.) with dorsal 

 and ventral margins almost parallel ; characteristic bristle on posterior 

 margin inserted below midpoint, this bristle about as long as greatest 

 width of digitoid. Movable finger or digitoid of clasper (F.) strongly 

 produced dorsocaudally ; twice as long as broad ; anterior margin be- 

 coming convex; three long bristles posterodorsally ; several bristles 

 on dorsal margin, posterior margin, and laterally; one or two thin 

 bristles on anterior margin. Distal arm of ninth sternum (fig. 51) 

 with dorsal (anterior) margin semimembranous proximally; apex 

 acute ; ventral (posterior) margin slightly sinuate, in the main very 

 gently convex ; bearing 3 or 4 long bristles and 15 to 20 shorter ones, 

 those near apex much shorter than others. 



Aedeagus (fig. 107).— Essentially as in hesperomys but with croch- 

 ets (CR.) much reduced, represented by short, broad Y-shaped 

 structures, the sagittate or dagger extension lost. Band of inner tube 

 (B.I.T.) slightly longer than in hesperomys. 



Female.— Vosterior margin of seventh sternum (fig. 50) with broad 

 lobe, below this fairly straight to ventral margin. Anal stylet three or 

 more times as long as broad ; with one long apical and one shorter 

 subapical bristle, and one ventrolateral bristle. (One female examined 

 apparently has two long apical bristles.) Head of spermatheca elon- 

 gate, oval, as long as, or longer than, tail (fig. 50, SP.). 

 Length.— Male, 2.2-2.4 mm. ; female, 2.8 mm. 

 Holotype.— Female U.S.N.M. No. 52900, from Peromyscus {leu- 

 copus noveboracensis Fischer?), Dubuque, Iowa. 



