A SUPPLEMENT TO THE REVISIONS OF 
THE DACETINE ANT GENERA ORECTOGNATHUS 
AND ARNOLDIDRIS , WITH KEYS TO THE SPECIES 1 
By W. L. Brown, Jr. 
Museum of Comparative Zoology, Harvard University 
The Orectognathiti are a small group of dacetine ants 
found in the Australopapuan area, grouped into two genera, 
Orectognathus Fr. Smith and Arnoldidris Brown. Pre- 
vious revisions (Brown, 1950, 1953) have recognized nine 
species in the first and four in the latter genus; of these, 
I had been able to study directly only six species of 
Orectognathus from satisfactory material and under favor- 
able conditions. Recently, however, I have been able to 
see additional material collected by E. 0. Wilson in New 
Caledonia and New Guinea, and in eastern Australia by 
Father C. Mercovich and myself. Furthermore, through 
the kind help of Curator Elisabetha Bajari of the Hun- 
garian National Museum, I have been loaned the types 
of Orectognathus csikii Szabo, Arnoldidris biroi (Szabo), 
A. horvathi (Szabo) and A. chyzeri (Emery). During a 
hurried visit to the British Museum, I saw the type of 
Arnoldidris longispinosus (Donisthorpe) , but was unable 
to make a proper sketch or notes beyond the affirmation 
of the species as a true Arnoldidris of the biroi group. 
In the present paper, I propose to add two new orectog- 
nathite species and to offer notes on the characters, 
biology and distribution of some older ones. For the sake 
of a complete treatment and full keys, I have included 
notes and a figure of the manuscript species as derived 
from the characterization of (0. nigriventris) by Father 
Mercovich. It may be some time before the formal de- 
scription of Father Mercovich’s species appears in print, 
and neither he nor I intend that the preliminary informa- 
1 Published wLh the aid of a grant from the Museum of Comparative 
Zoology at Harvard College. 
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