258 
Psyche 
[Vol. 90 
weakly concave sides, nearly straight apical margin, and one free 
corner rounded, the other rectangular. Mandibles thicker, particu- 
larly in the stretch between the obsolescent basal angle and the 
submedian tooth, which is also feebly convex mesally (concave or 
straight along mesal margin in M. julivora). Labrum toothed as in 
M. julivora. 
Sculpture as in M. julivora, but small, widely spaced punctures 
(diameter 0.01-0.02 mm) are perhaps more distinct on head and 
trunk. A small patch of longitudinal costulation lies below spiracle 
on side of propodeum (as in M. julivora). Posterior corners of 
propodeum less broadly rounded, tending more towards angularity, 
both in side and dorsal views, than in M. julivora, and both the 
pilosity and pubescence seem to be less copious and a trifle longer. 
Color deep brownish red; legs yellowish red; antennae and man- 
dibles dark yellowish brown. 
Holotype and only known specimen (MCZ) a stray collected from 
rotten wood at Joangeng, a village in the Mongi River Watershed of 
the Huon Peninsula, Papua New Guinea, at about 1500 m, 7-8 
April 1955, in montane rain forest, leg. Wilson, No. 752. 
We describe this species with some misgiving because it is based 
on a unique, and because it is so similar to M. julivora, especially to 
the largest (Baiyer River) specimen of the lattter. The mandibles, 
however, differ enough that we feel inclusion of the big Joangeng 
specimen in M. julivora would unduly strain the concept of that 
species. Further collections will of course help to demonstrate 
whether our decision is correct or not. The name media refers to the 
size of the body, intermediate in the tenuis group between M. tenuis 
and such large forms as loriai and gigas. 
Myopias concava new species 
(Figs. 4, 18) 
Diagnosis, worker and queen: A medium-sized, stout-bodied spe- 
cies with head slightly broader than long, widest just behind eyes. 
Median labral tooth absent, but an erect apical tooth on each labral 
lobe. Eyes of worker large and multifacetted, occupying more than a 
quarter of the length of the sides of the head. Posterior margin of 
head weakly concave; sides convex. Median lobe of clypeus distinct 
but very short, rectangular. Mandibles short and stout, each with 2 
