1929] 
The Ant Genus Rhopalomastix 
99 
Forel. To be sure, the basitarsi are not dilated as in Melis- 
sotarsus, but the second to fourth joints are unusual in being 
extremely short, obliquely prolonged on each side and over- 
lapping. 
In regard to the palpal joints, I am unable to add any- 
thing to Forel’s statement that in the worker the “labial 
palpi are two-jointed, the maxillary palpi not to be found.” 
Perhaps the latter are present but greatly reduced. 
The peculiarities of the wing-venation are inadequately 
described by Forel. As will be seen from Fig. le, the fore 
wing is peculiar in completely lacking the costal vein basal 
to the pterostigma, in the shape of the pterostigma, and the 
length of the cubital cell which exhibits traces of a division 
into two. Forel compares the venation with that of Solenop- 
sis, but it is clearly more like that of Myrmecina, especially 
in the structure of the radical cell. According to Arnold, the 
apterostigma is almost obsolete in Melissotarsus. 
Both the genera of Melissotarsini have essentially the 
same nesting habits, as shown by the following notes. 
Escherich took all phases of the typical Rh. rothneyi under 
bark. Viehmeyer cites Overbeck as having taken the form 
which I have described as the subsp. johorensis from several 
nests in the dead twigs of mango (Mangifera) and in the 
bark of durion trees (Durio zibethinus) , and Dr. Kalshoven 
has sent me the following note in regard to the subsp. 
javana: “The Rhopalomastix (gl04) was collected from a 
sample of bark of a dying Mangifera indica , which was for- 
warded to our Institute at Buitenzorg by Dr. Loos, the land- 
bouwconsulent (agricultural expert) at Bondowoso (Res. 
Besoeki, Eastern Java). Dr. Loos wrote us that the ants 
were burrowing in the bark of the dying tree. The bark was 
riddled by the insects over half the circumference of the 
tree and at least as high as he could reach. Numerous pupae 
were seen. The ants, however, were not considered to be the 
cause of the death of the tree.” This note shows that the 
Rhopalomastix colonies may be very populous. That Melis- 
sotarsus has very similar habits may be inferred from 
Arnold’s remark (p. 190) on M. beccarii , which was taken 
at Durban, “nesting under bark in moderately populous 
colonies.” 
