1957] 
Brown — Orectognathus and Arnoldidris 
25 
in a drier, more open part of the forest. Other samples 
from Ciu came from soil cover berlesates. 
Orectognathus phyllobates sp. nov. 
(Figure 4) 
Holotype worker: TL 4.5, HL 1.12, HW (disregarding 
compound eyes) 0.97 (Cl 87), scape L 0.78, greatest 
diameter of eye 0.24, ml 0.64 (mi 57), wl 1.14 (occipital 
lobes overlap pronotum by about 0.12 mm., an amount 
subtracted from WL to obtain TL), petiole L in side view 
0.47, postpetiole L 0.22, gaster L 1.00, propodeal spine L 
0.28 mm. 
Form as shown in Figure 4. Occipital lobes concave 
inside the bluntly carinate continuations of the frontal 
carinae; vertex convex, bituberculate centrally. Maximum 
depth of head about 2/3 hl. Anteocular teeth well de- 
veloped, acute and sharply elevated. Mandibles strongly 
concave inside, even more so than in (O. nigriventris ) , 
the heavy preapical convexities correspondingly stronger. 
The three apical teeth subequal in length; upper tooth 
diverging from the lower pair as seen in end-on view of 
mandible. 
Alitrunk in the typical Orectognathus plan; pronotum 
depressed and marginate, with a pair of strong, acute, 
anteriorly curved teeth, incrassate basally; rear of pro- 
notum sloping through a gradual curve up to the mesono- 
tum. Mesonotum raised in the usual manner; anterior 
tubercles low, blunt; posterior pair higher, more denti- 
form, though with extreme tips blunt. Propodeal spines 
strongly elevated, approximately straight in side view, 
diverging and slightly outcurved in dorsal view. Petiolar 
teeth strong, acute, curving posterodorsad, but with apices 
deflected. Postpetiole subtrapezoidal in dorsal view (Figure 
4) ; in side view semiglobose in outline. 
Body generally smooth and shining, with widely scat- 
tered inconspicuous punctulae in some areas. Sides of 
posterior alitrunk with some rather irregular rugosity; 
metanotal groove with short longitudinal costulae; costu- 
lae at base of gaster very short, almost obsolete, confined 
