18 
Psyche 
[March 
tion concerning the species offered here should be con- 
sidered as constituting publication of (O. nigriventris ) . 
The aid of Curator Bajari, Father Mercovich and Dr. 
Wilson in preparing this supplement is gratefully ack- 
nowledged. The abbreviations of measurements and in- 
dices, and also of places where specimens are deposited, 
are as in my other works on the dacetines, including the 
Orectognathus revision (Brown, 1953). 
Arnoldidris biroi (Szabo) 
A single worker taken by Wilson at Wamuki, about 
800 m. altitude, Mongi Watershed, Huon Peninsula, New 
Guinea, agrees well with a type from the Hungarian 
National Museum. Wilson’s worker was taken from a 
shrub in rain forest, foraging during daylight hours. 
Arnoldidris horvathi (Szabo) 
The type collection of this ant, possibly the most bizarre 
formicid known, remains the only sample known. The 
type confirms the figures of Szabo in all important respects. 
Arnoldidris szentivanyi sp. nov. 
(Figures 1, 2) 
Holotype worker: tl 6.1, hl 1.38, hw 1.18 (ci 86), 
scape L 0.92, max. diameter of eye 0.27, ml 0.80 (mi 58), 
Wl 1.66 (occipital lobes overlap pronotum about 0.17 mm., 
an amount duly subtracted from tl), petiole L in side 
view 0.83, postpetiole L 0.35, gaster L 1.25, propodeal 
spine L 1.12, gaster w 1.02, pronotal w 0.71 mm. 
Form as shown for the paratype in Figure 1 and Figure 
2. Occipital lobes each bordered dorsolaterally by a round- 
edged carina, indicated in the figures. Mesepisternum on 
each side extended as a shallow translucent lobe over- 
lapping the upper posterior part of the fore coxa. Meta- 
pleural lobes rounded. Petiole very slender, gently arched, 
Explanation of Plate 1 
Figures 1 to 4. Figure 1, Arnoldidris szentivanyi sp. nov., paratype 
worker, dorsal view. Figure 2, same, side view of posterior half of head. 
Figure 3, ( Orectognathus nigriventris Mercovich ms.), worker from type 
series, dorsal view of half of head. Figure 4, O. phyllobates sp. nov., 
holotype worker, dorsal view. All to same scale. Drawings by Nancy 
Buffler. 
