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R. TRAUB 
Mt. Kinabalu, North Borneo. Rattus alticola was also found only between these points. It 
should be pointed out that collections were somewhat limited immediately above and below 
those points. This flea was never taken in the lowlands, and of course Rattus alticola is not 
know T n in such an environment. Rattus sabanus , R. cremoriv enter , R. whiteheadi , R. rattus , R. 
rajah , and R. rapit which were taken below 4,000 feet invariably lacked this flea. 
It may be of interest to note that 12 Rattus alticola , collected by the author in the Cameron 
Highlands in Malaya at 5,000 feet (Harrison and Traub, 1950) did not carry any species of 
Sigmactenus . 
Notes on the Genus Sigmactenus 
It can now be established that certain features can be added to the generic characterization 
of Sigmactenus. Among these are: the short antennal bristles in the male and the fact that, 
while most of these are short in the female, at least one bristle invariably seems to be as long 
as the club; the downward extension of the pronotum over the prosternosome ; the well- 
developed squamulum ; uncoiled penis rods ; the short compact endchamber of the aedeagus ; 
and the relatively large, although weakly sclerotized, eighth sternum of the female. The dense 
tuft of bristles on the apex of the first antennal segment of the male in the two described species 
is an interesting secondary sexual characteristic. This, however, may not be of generic value. 
The same is probably true of the secondary divisions of the antennal club. The aedeagus of 
Sigmactenus is typical for the subfamily Leptopsyflinae. Particularly characteristic are the 
compact endchamber and the relatively greatly enlarged crochet. The movable dorsolateral 
lobes (fig. 4, DL.L.) also occur in Peromyscopsylla and in Paractenopsyllus Wagner, 1938. 
Neopsylla luma n. sp. (figs. 13-21). 
Diagnosis. — Related to Neopsylla dispar Jordan, 1932, as evidenced by the following 
characters: some of the dorsolateral bristles on the hind tibiae forming a false comb; mesal 
spiniforms on metacoxae ; three row T s of occipital bristles ; the sinus separating Pi and P2 of male 
clasper broad, somewhat broader than deep; the absence of true spiniforms on the distal arm 
of the male ninth sternum. Readily separable from N. dispar in that: (1) the distal arm of the 
ninth sternum (D.A. 9. fig. 20) apically narrowed, about six times as long as broad at distal 
fifth or sixth instead of merely thrice as long; (2) digitoid, or movable finger (fig. 18, F) shorter, 
broader and more rounded, about three and one-half times as long as broad, scarcely extending 
beyond the apex of P2, its caudal margin evenly and deeply convex, lacking a subtruncate 
ventral margin; in N. dispar the digitoid is 4! times longer than broad and its apex 
clearly extends beyond that of P2 ; there is a subtruncate ventral margin and the posterior margin 
proximally is only slightly curved ; (3) the seventh sternum of the female caudally possessing a 
dorsal lobe which is broad, the sinus separating the dorsal from the ventral lobe being very 
broad, subrounded; in N. dispar , the upper lobe is long and narrow, acute, while the sinus is 
also acute. 
Description. — Head (fig. 13, Male.) Frontoclypeal margin evenly rounded but with small but 
distinct acute median tubercle. First pre-antennal row consisting of 8-9 fairly long thin bristles, 
in addition at times with one or two smaller ones bordering antennal groove. Second pre-antennal row of 
four larger bristles, the lowest ventromarginal and the uppermost contiguous with antennal groove. Eye 
virtually completely vestigial. Mesal spine of genal ctenidium acuminate, longer than broader lateral 
spine, in ratio of 7-8 to 5. Genal process masked by ctenidium. Maxillary lobe extending to near apex of 
maxillary palpi. Labial palpi five-segmented but first segment at times appearing secondarily divided. 
True segments two to four together only slightly longer than first and fifth; the palpi extending slightly less 
than three-fourths length of first coxa. First antennal segment with a proximal row of anteromarginal 
bristles; with a subapical row of small thin bristles; proximad to these one or two similar ones. Second 
antennal segment with an apical fringe of short bristles in male, not extending beyond third segment of 
club; in female, the subdorsal bristles slightly longer, reaching to near midpoint of club. Postantennal 
region with three full rows of bristles, usually arranged 7~7(6)-6(7);*with a row of small bristles delimiting 
antennal groove. 
STUD. INST. MED. RES. 
