1927] The Slave Raids of Harpagoxenus americanus 
15 
slave-raids was ideally situated for such work. It was in a 
crevice in one of the many out-jutting ledges of rock which stud- 
ded a slope above a small pond. Jammed into the crevice was 
a small flake of stone which formed a little shelf on the perpen- 
dicular face of the ledge, and between this flake and the solid 
rock the nest was constructed. The entrance had been enclosed 
by a carton of lichens, perforated in the center by an almost 
circular aperture. Eleven feet away under the bark of a small 
log which rested on the ledge was the nest which the raiders 
visited. Between the two nests the ledge was bare except for 
large black lichens and occasional leaves and fragments of bark. 
The progress of the raiders could therefore be followed with the 
greatest ease, an important consideration when dealing with 
small, slowly moving insects. 
The first raid was observed on August 4th. Arriving at the 
nest at 3:00 P. M. I noticed a crowd of Leptothorax and Har- 
pagoxenus about the entrance. At 3:02 a Harpagoxenus arrived 
with a pupa. Another at 3:04. In both cases the longispinosus 
workers crowded about the returned raider apparently attempt- 
ing to relieve it of its burden. A third pupa was brought in at 
3:08 and carried directly into the next by the Harpagoxenus, 
which turned and backed into the entrance pulling the pupa in 
after it. At 3:25 a Harpagoxenus arrived with a callow. Another 
with a pupa at 3:26. In each case the raider entered the nest 
with its burden in the manner just described. During transpor- 
tation the pupae are held in such a way that they project forward 
and upward in front of the head of the raider. 
The log in which the raided nest was located was small and 
badly decayed. The bark had loosened with the decomposition 
of the underlying wood and, as was later determined, just under 
the bark in a roughly oval excavation was the raided nest. To 
this the Harpagoxenus gained access through a rupture in the 
bark several inches away. The actions of the raiders on ar- 
riving at the log were somewhat disconcerting. They entered 
as nonchalantly, if I may be pardoned an anthropomorphic 
term, as though it had been their own nest. However any doubts 
as to the nature of their visit were quickly dispelled by the 
action of the Leptothorax. About ten inches from the point 
