1929 ] The Ant Genera Gesomyrmex and Dimorphomyrmex 9 
is sufficiently developed to enable me to determine its main 
peculiarities. As will be seen from the figure, it is broader 
than long, with evenly rounded, convex, postocular region; 
the eyes are very small, for a male, not longer than the 
cheeks, not very convex and situated at the sides of the 
head; the ocelli are moderately large but fiat; the antennal 
insertions are very far apart and near the anterior orbits; 
the antennal scapes are short and abruptly bent outwards 
at their tips (probably a pupal character), the funiculi 
short, thick and distinctly 6-jointed ( !), instead of 7-jointed 
as in the worker; the clypeus is rounded and slightly pro- 
jecting in the middle; the mandibles small, narrow, edentate 
and rather blunt. The specimen is of considerable interest 
because no other male of the genus is known, though Mayr 
carefully described and figured what he took to be the male 
of G. hoemesi from a rather poorly preserved specimen in the 
Baltic amber. Although we must allow in my description of 
the male semipupa of G. kalshoveni for later pupal changes 
(especially, perhaps, in the number of funicular joints), it 
is clear, nevertheless, that the male of this species is deci- 
dedly different from Mayr’s specimen. This has enormous 
eyes, constituting the greater portion of the head, very 
minute pointed mandibles, very slender 11- jointed antennae 
and very minute genital appendages. Although the wing- 
venation agrees closely with that of the female G. luzonensis, 
I believe that Mayr’s specimen must belong to some other 
hitherto unidentified Formicine genus. 
Two other fossil ants supposed to be allied to Gesomyr- 
mex may be briefly considered in this connection. The first 
of these is a large-eyed worker which Emery described from 
the Sicilian amber of Miocene age, as Gesomyrmex corniger. 
His description and figures, however, show that this insect 
cannot be included in the genus Gesomyrmex. The shape of 
its head, mandibles and petiole, the presence of long oblique 
spines on the epinotum, the very long maxillary palpi, the 
abundant pilosity, peculiar rugosity of the head, pro-and 
mesonotum, the blackish coloration and the possibility that 
its antennae may be really 9 or 10 instead of 8-jointed, led 
me to place it in a distinct genus, Sicelomyrmex. Apart from 
the peculiar recurved horns at its posterior corners, the 
head of this ant is more suggestive of the Neotropical 
