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Psyche 
[September-December 
distinct anteriad on each segment, while the costulae predominate 
posteriad; this is especially true in the eastern (Surinam and Guy- 
ana) samples, in which the costulae become virtually obsolete on 
the anterior half of each tergum. The sculptured surface is opaque 
to sericeous-opaque, depending on magnification and lighting. The 
fourth gastric tergum, largely retracted, appears to be finely and 
superficially punctulate and subopaque. Underside of gaster shin- 
ing, finely reticulate. 
Other minor average differences from O. bauri are as follows: 
Costulae of the head and trunk a trifle more strongly shining 
(about 6-7 costulae per 0.1 mm square on each side of the vertexal 
midline). Striation of petiolar node finer than in most bauri, 
oblique. The node itself is a little less “dome-shaped”, less convex 
in outline behind, and therefore more as in O. haematodus, but the 
metasternal process is low, and not produced into paired sharp 
teeth, as it is in O. haematodus. 
Apical spine of petiole straight and only weakly back-tilted. 
Pilosity and pubescence copious and distributed much as in O. 
bauri, but on the average a trifle shorter and less dense; 4-8 stand- 
ing hairs on pronotum; standing hairs of body about 0.2-0.45 mm 
long. Mesopleura obliquely striate, with a few coarse punctures in 
the mid-section; in the eastern samples, the mesopleural sculpture 
is effaced, smooth and shining in the mid-section, and the punc- 
tures here are smaller. Color black in Ecuadorean samples, with 
dark brown legs; antennal funiculi and tarsi yellowish-brown. 
Eastern samples dark reddish-brown to piceous (some possibly 
faded), funiculi and tarsi yellowish-brown. Palpi segmented 4,3, 
In some specimens, the longitudinal striation of the metanotum 
even continues for a short distance onto the anterior part of the 
propodeum. 
Queen and male unknown. 
Holotype (Museum of Comparative Zoology at Harvard Univer- 
sity, Cambridge, Massachusetts, USA) and one paratype worker 
from a rain forest litter berlesate taken 20 km south of Tena, Napo 
Prov., Ecuador, 11 July 1976, by S. and J. Peck, sample no. B-360. 
Two paratype workers from Surinam: [apparently near Parama- 
ribo], “Sectie O,” on forest floor, D. C. Geijskes, 15 July 1942. 
One paratype worker from southern Guyana: Oronoque River, 
2°41'N, 25 July 1936, by N. A. Weber, no. 594. Paratypes in MCZ 
and U.S. National Museum of Natural History, Washington, D.C. 
