NO. 4 FLEA GENUS PEROMYSCOPSYLLA — JOHNSON AND TRAUB I5 



Ctenopsylla rawalliensis (sic) Wagner, Canadian Ent., vol. 68, p. 205, fig. 10, 

 1936. 



Peromyscopsylla ravalliensis Jeluson and Good, U. S. Publ. Health Serv., Nat. 

 Inst. Health Bull. 178, p. 122, 1942. — Hubbard, Fleas of western North 

 America, pp. 329, 332, fig. 199, 1947 (part, some of records listed are 

 hesperomys adelpha (Rothschild, 1914). — Holland, Siphonaptera of Canada, 

 pp. i/S, T^77, figs. 316-318, map 41, 1949. 



This subspecies of hesperomys is somewhat larger than the others 

 and may be further distinguished from the other forms by a number 

 of relative differences. In both male and female (but more marked in 

 the male) the dorsum of the mesonotum is thickly covered, especially 

 anteriorly, with rather coarse, erect bristles (fig. 21), not with much 

 finer and/or less abundant erect bristles (figs. 4, 22). The anterior 

 margin of the head is more vertical, and the angle at insertion of the 

 labrum is less marked than in the other subspecies (figs. 12, 14) ; the 

 female (and more rarely the male) may have four frontal spiniforms 

 rather than three (fig. 12). In the male the ventral margin of P. is 

 more than one-half the length of the dorsal margin, the ventral margin 

 measuring 110-119 microns, the dorsal margin measuring 167-181 

 microns, not 72-110 microns (ventral margin) and 134-167 microns 

 (dorsal margin), as is the case in hesperomys adelpha and h. pacifica; 

 the digitoid (figs. 18-20, F.) is consistently larger than the two sub- 

 species mentioned above, measuring in length 81-91 microns, and in 

 breadth 143-162 microns, i.e., markedly less than two times as long 

 as broad ; the area of greatest width at middle. In the male, the 

 eighth sternum bears on the upper lobe almost always at least three 

 long bristles and one or two smaller ones ; the sinus is deeper and the 

 upper lobe is broader than in h. hesperomys (fig. 34). The sinus on 

 the posterior margin of the female seventh sternum varies greatly from 

 a very narrow, small ventral sinus to a much larger sinus located more 

 laterally (figs. 27 (allotype), 28). 



Holland (1949) has stated that the usual hosts of h. ravalliensis are 

 members of the genus Neotonia, other records usually being from 

 animals closely associated with wood rats. This certainly appears to 

 be the case ; the only records v/e have other than Neotoma are from 

 animals to be found in the same habitat as Neotoma, and taken in 

 association with it. Hubbard's records (1947) of this flea from Neo- 

 toma, Wallowa, Oreg., indicate that the likely range of hesperomys 

 ravalliensis is the more northerly Rocky Mountain region, and west 

 into eastern Oregon. However it is felt that some records of h. 

 ravalliensis from wood rats bear further checking, since undeniably 

 this subspecies could be confused with h. adelpha, particularly since 



