1956] 
Gregg — Ceylon Myrmoteras 
43 
kemneri. Further, the 5th, 7th, and 9th teeth in ceylonica 
are distinctly smaller than the ones with which they 
alternate, while in kemneri only the 8th appears to be 
smaller (Fig. 1). In profile, the dorsal surface of the 
pronotum is flat in the center and passes through distinct 
angles to slope both anteriorly and posteriorly, whereas 
in kemneri the pronotum shows an even and relatively 
low convexity from front to back. The mesothorax of 
ceylonica is short in side view, being almost quadrate, 
and with a flat dorsal contour that depresses slightly to 
the meso-epinotal suture. The same structure in kemneri 
is decidedly elongate and shallowly saddle-shaped with 
prominent mesonotal spiracles. The epinotum of ceylonica 
is about as high as it is long with an even curvature 
dorsally, while that of kemneri is very much longer than 
high and its dorsal contour arches upward to the rear. 
Probably the most distinctive feature separating these 
two ants is the petiole. In ceylonica the anterior and 
posterior peduncles are quite short, the scale is narrow 
antero-posteriorly, and high, with flat, nearly vertical 
front and rear surfaces ; the crest is truncated and margined 
anteriorly and posteriorly with minute but definite ridges, 
which give the summit of the node an appearance of being 
depressed or concave. By contrast, in kemneri, the poste- 
rior peduncle is longer than the anterior, the anterior and 
posterior surfaces of the node are rounded and sloping, 
and the crest is evenly rounded in all directions. 
Sculptural features of the head in the two species seem 
to be remarkably similar, as they are heavily granulate 
and give the surface a coriaceous and opaque appearance. 
The same condition is true of the pronota also, though 
this structure is a little more shining at least in ceylonica 
owing probably to the large size of the granules. The 
mesonotum and epinotum of ceylonica, unlike the smooth, 
opaque, almost sculpturless corresponding structures of 
kemneri, are furnished with pronounced rugae that are 
more or less longitudinal on the mesonotum, but very 
heavy and distinctly transverse on the dorsum of the 
epinotum. Rugae of the mesopleurae and epinotal pleurae 
are longitudinal but finer in texture. The interrugal 
