1929] The Ant Genera Gesomyrmex and Dimorphomyrmex 
7 
G. kalshoveni must be very close to the form described by 
Andre as G. chaperi from the minima and “D. janeti” from the 
maxima and media worker. He gives the length of the 
minima as 3.5 to 4 mm., of the media as 3.5 mm. and the 
soldier as 6 mm. If his descriptions were drawn from cabinet 
specimens the fact that the largest minima was longer than 
the media may be explained on the supposition that the 
gasters of the two specimens had contracted unequally on 
drying. Such differences are, of course, frequent also in the 
gasters of living or alcoholic specimens of the same caste, 
owing to variable distension of the crop. The maxima of 
kalshoveni differs from that of chaperi in lacking the lateral 
auriculate expansions of the clypeus, in possessing longer 
funicular joints and nonpigmented ocelli, a decidedly more 
convex pronotum and in having the stubby hairs on the 
front and clypeus simple and truncate instead of bifid or 
multifid at their tips. Andre describes these hairs as “ap- 
pearing as if surmounted or even crowned with minute 
spines.” Emery has cited G. chaperi (as D. janeti) from 
Sumatra, but it is not improbable that his specimens be- 
longed to the Javan rather than to the Bornean species. 
The new Gesomyrmex differs from G. howardi in the 
shape of the petiolar node, which in the latter (Fig. 1, 1 and 
m) is much thicker above, with rounded, entire border, in 
the epinotum which is shorter in howardi, with much less 
convex base and with the base and declivity subequal. The 
sculpture of howardi is decidedly coarser, especially on the 
epinotum and pleurae, so that the surface is more opaque. 
The color is also darker and more brownish or sordid than in 
kalshoveni and chaperi. There are distinct striae on the front in 
the media and minima of howardi. It is, of course, not im- 
probable that all four living species of Gesomyrmex, in- 
cluding G. luzonensis, which is known only from the female, 
may prove to be merely so many local races (sub-species or 
varieties) , when sufficient material of these forms has found 
its way into our collections. 
It would be interesting to revise the fossil species of 
Gesomyrmex in the light of the preceding discussion. Of the 
material which I studied in 1913 and soon afterward re- 
turned to the Konigsberg museums, I retained only a single 
block of amber containing a large and a small worker of “D. 
