36 
Psyche 
[March 
queenslandensis Forel 1915, which is synonymized below. These two 
forms differ only slightly, except in coloration, and distributional 
evidence suggests that the bicolored form is a character-displaced 
variant, produced wherever the range of quadridentatus overlaps that 
of wheeleri (see fig. 15, plate 3, and discussion on p. 53). Like 
their northern congeners the quadridentatus-g roup species are known 
only from rain forest, usually at elevations of ■+ 1000 ft. 
Available biological information is given in the taxonomic section 
to follow. Nesting apparently occurs in rotting logs in all species 
except wheeleri, colonies of which are usually located in the soil, under 
stones. Feeding and foraging behavior have not been extensively 
studied, but the bicolored form of quadridentatus forages nocturnally, 
in the open, on logs, tree trunks and low foliage. It appears that 
wheeleri may restrict its foraging activity to the soil and leaf litter, 
since strays have not been taken elsewhere, in spite of extensive search 
by the author. 
All Australian Pristomyrmex types are workers, and the females 
are known for all species except foveolatus ; I have seen no male 
specimens. Larvae of a North Queensland species were described by 
G. C. and J. Wheeler (1954). I have been unable to locate adults 
from the series involved ; they would conform to the foveolatus-group 
diagnosis according to their collector, Dr. W. L. Brown, Jr. 
This study is based on material from the Museum of Comparative 
Zoology collection at Harvard University, from Entomology Division, 
CSIRO, Canberra, The National Museum of Victoria, Melbourne, 
and the collection of Rev. B. B. Lowery, S.J., Sydney. 
MEASUREMENTS AND INDICES 
The following abbreviations are used in the descriptions below. 
Measurements were prepared using a stereomicroscope fitted with an 
eyepiece scale, reading directly in units of 0.1 and 0.01 mm at 100 X 
magnification. The measurements cited are the maxima obtained after 
a series of trials, a fact of special importance when dealing with HL 
and WL. 
HL Maximum head length, frontal view, from apex of median 
clypeal denticle to median occipital border. 
HW Plead width, frontal view, including the eyes. 
Cl Cephalic index (HW X ioo)/HL 
SL Scape length, excluding articular boss and condyle ( hut in- 
cluding the expanded lamella at base of shaft). 
SI Scape index (SL X ioo)/HW 
PW Pronotum width, anterior view, immediately below the bases 
of the pronotal spines. 
