40 
Psyche 
[February 
THE OCCURRENCE OF FORMICA FUSCA L, 
IN SUMATRA. 
By William Morton Wheeler. 
In a preceding number of Psyche (Vol. 29, Aug. 1922, p. 
175) I cited the occurrence of two common North American 
ants, Formica fusca L. and F. neogagates Emery, as having been 
taken by Dr. J. W. Chapman at Dumaguete, on the Island of 
Negros in the Philippines, and conjectured that they might have 
been introduced by commerce. Recently I have come to doubt 
the provenience of the specimens to which I referred. It seems 
that when he left the Bussey Institution to teach at the Silliman 
Institute in Dumaguete, Dr. Chapman was supplied by our 
laboratory with a number of empty vials to be used in collecting 
ants and other insects. Possibly two of these vials contained 
some specimens of F. fusca and neogagates that had been collected 
near Boston by one of the students and had been accidentally 
included among the material amassed by Dr. Chapman near the 
Silliman Institute. Since all this material was collected in a 
small area he did not provide the individual vials with locality 
labels. Until, therefore, the species of Formica above mentioned 
are again taken at Dumaguete, it is inadvisable to include them 
among the Philippine ant-fauna. No such doubt, however, can 
arise in regard to the species of Formica discussed in the fol- 
lowing paragraphs. 
Among a number of ants collected for me by Dr. David 
Fairchild and his son Graham Fairchild in Northern Sumatra, I 
find a series of twelve workers, which evidently belong to the 
common circumpolar Formica f usca, though they may be regard- 
ed as representing a distinct variety, var. fairchildi var. nov. 
These specimens were taken by Dr. Fairchild March 8th, 1926 
above Kota Dah, at an altitude of 4000 ft., in a pine forest. 
Careful comparison with many specimens of the typical fusca 
reveals only the following slight differences: Body averaging 
slightly smaller (4-5 mm.); funicular joints of the antennse a 
little shorter. Border of petiole distinctly sharper and more 
compressed. Bristles on the flexor surfaces of the middle and 
