166 
Psyche 
[June 
GUESTS OF ECITON HAMATUM (FAB.) COLLECTED 
BY PROFESSOR W. M. WHEELER. 
By W. M. Mann, 
Entomologist, Taxonomic Investigations, U. S. Bureau of En- 
tomology, Washington, D. C. 
Through the kindness of Dr. Wheeler I have been able to 
examine the inquilines which he collected when he discovered a 
cluster of the army ant, Eciton hamatum, on Barro Colorado 
Island, Panama. A description by Dr. Wheeler of the cluster 
and of the hitherto unknown female is now in press. 
There were among the ants a number of beetles, one Sta- 
phylinus (sens, lat.) sp., two species of Erchomus and an En- 
domychid, Rhymbus sp., which were probably merely resting 
among the branches that held the cluster, as well as the new 
forms described herein which were evidently true guests. 
Though Eciton hamatum is one of the commonest of the 
army ants, this is, as far as I know, the first record of a cluster 
being examined. The actual files of hamatum, numbers of which 
I have watched, contain few guests compared with the files of 
of the equally common E. burchelli, and it is curious that the 
genus Ecitophya, so common with the latter, is very rare with 
hamatum. 
I have included the description of a new species of Tylois 
from Guatemala, long in the National collection. 
The holotypes of the new species are in the National Mu- 
seum. 
STAPHYLINIDiE. 
Xenocephalus panamensis, sp. nov. 
Length 7 . 5 mm. 
Very near X. clypeatus Wasm. 
Castaneous, shining; microscopic pubescence lacking on 
pronotum, finest and very sparse on elytra, more abundant on 
abdomen, ventral surface, and legs; first ventral sclerite of ab- 
domen with coarse, elongate foveolate punctures and semi- 
recumbent short setae; second with a row of separated setigerous 
