72 
Psyche 
[March 
I climbed the tree, which was only about 5 meters high, and soon 
found the nest about 3 meters up. Where two of the gnarled branches 
crossed, a thick pad of lichens surrounded the place where they 
touched. Forcing the branches apart, I found a rotted-out pocket, 
evidently caused by their rubbing together in high winds. The cavity 
extended downward several centimeters into one of the branches, and 
it was full of the ectatommine ants with brood and many of the 
round white arthropod eggs; I estimate that I removed or saw at 
least 200 workers, and there may have been more. The nest was very 
inconveniently placed, and the branch was too thick to break or cut 
with the small knife I had along, so I had to be satisfied with what 
I could extract by means of a twig wetted with alcohol, and with my 
fingers and forceps. 
A few minutes later along the trail, I found the entrance to 
another nest in a small tree, also about 3 m above ground, and like 
the first one of that day, also in a rot hole covered with lichens. 
I took a few workers from near the entrance, and later found two 
foraging workers on the hard-packed earth of the trail. Further 
observations were made impossible by a sudden torrential rain, and it 
was only with great difficulty that I got back down off the mountain, 
partially dried out my clothes, and reached the airport in time for 
the flight to India. 
My hosts in Calicut, Drs. A. Benedict Soans and Joyce Soans, gave 
me access to a stereomicroscope, and I quickly learned that the ecta- 
tommines I had were not Gnamptogenys , but Proceratium! I offer 
a formal description of the new Proceratium species, followed by a 
discussion of its relationships and its evolutionary and zoogeographic 
significance. 
Proceratium avium new species 
Figs. 1, 2 
Holotype worker: TL 4.8, HL 0.96, HW 0.94 (Cl 98), ML 
0.32, scape L 0.93, greatest diameter of eye 0.09, WL 1.43, L 
petiole in side view 0.60, L petiolar node as seen from above 0.47, 
W petiolar node 0.47, L hind tibia 0.97, L hind metatarsus 0.81 mm. 
For head length (HL), measurement is taken from the anterior 
lateral corners of the head (clypeus) ; head width (HW) excludes 
the eyes, and is taken just behind them. The petiolar node length 
excludes the brief anterior peduncle and is taken from the approxi- 
mate base of the anterior nodal slope. The length of the gaster is 
