12 
Psyche 
[March 
Emery places the two genera in his sixth tribe, or first tribe 
of the section Euformicinse, which he bases on characters 
drawn from the gizzard (proventriculus). Unfortunately, he 
named this tribe Dimorphomyrmicini (his Dimorphomyrmii 
of 1895). Since the genus Dimorphomyrmex now passes into 
the synonymy, the tribe will have to be called Gesomyrmi- 
cini (Ashmead, 1905). This tribe, according to Emery, would 
contain besides Gesomyrmex only the genera Brachymyr- 
mex, Aphomomyrmex and Cladomyrma. The three latter are 
supposed to be so closely interrelated that they form to- 
gether the subtribe Brachymyrmicini, leaving Gesomyrmex 
to represent a subtribe by itself, to which Emery gave the 
same name as the tribe (Dimorphomyrmicini). He evidently 
based his tribe on the small number of antennal joints (8-9 
in the worker, 8-10 in the female) instead of the 12 observed 
in both of these castes in all Euformicine genera, except 
certain fossils (Dryomyrmex and Prodimorphomyrmex) . 
But the general habitus of Gesomyrmex is so different from 
that of Brachymyrmex, Aphomomyrmex and Cladomyrma, 
that its relationships would seem to be better expressed by 
regarding it as the representative of an independent tribe 
(Gesomyrmicini). This would necessitate raising Emery’s 
subtribe Brachymyrmicini to tribal rank. I believe that the 
tribe Gesomyrmicini would thus be more naturally placed as 
one of the series of tribes, including the Santschiellini Forel, 
Gigantiopini Ashmead and CEcophyllini Ashmead, which are 
all based on single archaic, relict genera of large-eyed ants. 
The fossils Prodimorphomyrmex and Dryomyrmex may, 
perhaps, be assigned to the Brachymyrmicini, but Sicelo- 
myrmex corniger should be regarded as the representative of 
an extinct tribe, the Sicelomyrmicini. 
We are still in the dark in regard to the habits of Geso- 
myrmex. The well-developed claws in the worker and female 
and the not infrequent occurrence of G. hoernesi in the Baltic 
amber, suggest that the genus is arboreal. Moreover, the 
structure and sculpture of the anterior portion of the head 
in the maxima and female and the peculiar stubby hairs on 
the clypeus are reminiscent of some species of Colobopsis 
and allied subgenera of Camponotus, which live in hollow 
twigs or small cavities in bark or wood. 
