88 
Psyche 
[March 
in L. ergatogyna the wingless laying female still possesses well de- 
veloped ocelli and a normal female thorax. In the genus Myrmecia 
similar series, ranging through increasing female microptery toward 
total aptery, can be assembled, culminating in the ergatoid-like gynes 
of, for instance, M. tarsata. In all these species, however, there is 
little evidence of any significant modification in the social structure of 
the colony, which remains at base a typically matrifilial community. 
Certain other ponerine genera referred to by Wheeler, however, 
may present a rather different picture. In the genera Diacamma , 
Streblognathus , and Dinoponera, and in some species of Rkytido- 
ponera, for example, distinguishable ergatogynes have not been 
reported. A male of a Philippine species of Diacamma has been 
described in copula with a form indistinguishable from a worker by 
Wheeler and Chapman (1922), suggesting that in this organism the 
normal reproductive may have been replaced by what is in effect a 
worker-producing worker. Our overall knowledge of the first three 
genera, however, is hardly sufficient to support even speculation about 
their social situations at present. For the genus Rhytidoponera, 
however, something more is known or knowable, and it may quite 
possibly represent a situation of considerable interest to the student of 
social evolution in the Formicidae. 
The Ponerine genus Rhytidoponera comprises an extensive but 
relatively compact series of species inhabiting the Australian and 
parts of the Melanesian and Malaysian areas, ranging from New 
Caledonia in the east through New Guinea and neighboring parts of 
Melanesia to Timor, the Moluccas, and the southern Philippines in 
the west and occcupying a large portion of the Australian continent 
and of Tasmania (Brown, 1954, 1958; Wilson, 1958, 1959a). They 
are members of the widely distributed ponerine tribe Ectatommini, 
bearing considerable resemblance in many respects to the generalized 
New World tropical genera Acanthoponera and Ectatomma , as well 
as to the pantropical Heteroponera, with the Old World components 
of which they may well have shared common ancestry. The females 
of Ectatomma and Acanthoponera, so far known, are of the normal 
winged form. Those of Heteroponera may be winged or ergatoid. 
In at least three species of Rhytidoponera, R. impressa, R. purpurea , 
and R. chalybaeae , typical winged queens are the rule. Normally a 
single queen is found in each colony examined in the field, and com- 
munities appear to be initiated by isolated dealated females following 
a normal Ponerine dispersion and mating flight. These species are 
confined in distribution to well-watered and warmer areas, ranging 
from New Guinea and eastern Queensland rain forest southward 
