76 
Pagels, Eckerlin, Baker, and Fies 
previously been recorded from this host in Virginia. Voucher specimens 
of Citellinema bifurcatum, Strongyloides robustus, and Syphacia 
thompsoni have been deposited in the Helminth Collection of the U.S. 
National Museum of Natural History with accession numbers 79566, 
79567, and 79568, respectively. 
The presence of only male S. thompsoni in the two squirrels that 
had this species deserves comment. Although life cycle data for this 
nematode are not available, it is generally agreed that male oxyurids do 
not survive more than a short time after the females have been fertilized. 
Consequently, females usually outnumber males, but we found 2 males 
and 1 1 males in the absence of females. A unisexual infection of 32 male 
S. thompsoni was reported from the red squirrel, Tamiasciurus 
hudsonicus (Erxleben), in Wisconsin (Tiner and Rausch 1949). It was 
suggested that the unusual sex ratio could be attributed to the occurrence 
in an unnatural host. Glaucomys volans is the type host for S. 
thompsoni, but the high prevalence in G. sabrinus suggests that the 
latter species also is a suitable host. Clearly, more data are needed to 
clarify the relationship between S. thompsoni and G. sabrinus . 
The Highland Co. specimens (both skin and skull), VCU 4629, 
female, and VCU 4630, female, measured respectively: total length 260, 
250; tail vertebrae 120, 110; hindfoot 35, 36; ear 24, 26. The only 
standard measurements available for the Grayson County specimen are 
length of tail vertebrae 139 mm and hindfoot 38 mm. The partial 
museum skin is deposited in the Virginia Commonwealth University 
Mammal Collection (VCU 4615, female). 
That G. sabrinus was only recently taken in the Laurel Fork area in 
Highland Co., which has been sampled periodically over many years, 
suggests that the squirrel is rare. However, it also suggests that the 
apparent rarity may at least in part reflect the difficulty in trapping this 
animal or the inadequacy of collecting techniques that have been used. 
Weigl (1978) found that G. sabrinus and G. volans occasionally occur in 
the same woodlot although perhaps only temporarily. Further, Weigl 
(1978) found in captive populations that G. volans was able to control 
nests more often than G. sabrinus could and that it was much more 
aggressive than G. sabrinus in defending home area. One of us (J.F.P.) 
handled and ear-tagged numerous G. volans at the Highland Co. sites 
before and after the captures of the northern flying squirrels. C. O. 
Handley, Jr. (personal communication) observed numerous individuals 
of G. volans at one of the sites as much as 50 years ago. The species 
have coexisted at Stuart Knob in West Virginia for at least 36 years 
(Stihler et al. 1987). However, again perhaps suggestive of its great 
rarity, low trappability, or temporary coinhabitance of the sites, we 
