4 8 
Psyche 
[March 
the author, and by the experienced Australian collector B. B. Lowery, 
S. J., (pers. comm.). 
On May 21-23, 1962, I established that the bicolored form is 
probably an exclusively nocturnal forager. During 4 days of intensive 
collecting in rain forest near Binna Burra, workers were never 
encountered abroad from nests during the day. At night, however, 
22 workers in seven samples were taken as strays, during about four 
hours total collecting. These specimens were all collected between 
two and six hours after sunset (the limits of the observation period), 
and all were in the open on the surfaces of widely separated rotting 
logs. Several further individuals were taken near the ground on tree 
trunks, and one was collected from foliage in a sweep-net. In several 
cases these individuals appeared to be following trails, but they were 
always well separated from each other, at distances of 14-20 cm. The 
ants moved slowly, their rate of progress being estimated at 10-15 cm 
per minute. The nature of the food was not determined. 
Relationships. See discussion on p. 35. 
4. Pristomyrmex wheeleri new species 
(Figs. 11-15, Plate 3) 
Type workers. The following description is based on the holotype 
and numerous paratypes from all parts of the distributional range 
given below. 
Dimensions (holotype cited first) : HL 1.14, 0.97-1.23 mm; HW 
1.26, 1. 04- 1. 40 mm; Cl 111, 108- 1 16; SL 1.11, 0.92-1. 14 mm; SI 
88, 81-90; PW 0.60, 0.51-0.67 mm; WL 1.09, 0.89-1.20 mm; 
Pronotal Spine L 0.17, 0.15-0.20 mm; Propodeal Spine L 0.35, 
0.27-0.39 mm; Petiole L 0.41, 0.36-0.44 mm; Postpetiole Height 
0.38, 0.31-0.43 mm. General features as in Figures 11 and 12, and 
Plate 3 (upper figure). Similar to P. quadridentatus, as described 
above, but differing in the following features: 
1. Generally larger size (HW 1.04- 1.40 mm, opposed to 0.88-1.14 
mm in quadridentatus ) , with much broader head (Cl 108-116 against 
97-103), and lower Scape Index (81-90 opposed to 93-105). 
2. Inferior carina of antennal scrobe vestigial or absent. 
3. Pronotal and propodeal spines longer and more slender, in side 
view approximately sub-equal in length ; metapleural spines acute, 
rarely more than half as long as propodeals. 
4. Pilosity similar, the body hairs thicker and longer, petiolar 
peduncle with a single hair on each side, first gastric tergite naked. 
5. Color distinctive; head deep dark umber-brown. Mandibles, 
clypeus and antennae rich golden-brown. Remainder of body golden- 
brown, much like the self-colored form of quadridentatus , but more 
