The Ants of the Baltic Amber. 
67 
distinguished from all the preceding species by its 11-jointed antennse. 
It does not closely resemble the recent L. (Mychothorax) acervorum, 
except in this number of antennal joints and the mesoepinotal con- 
striction. 
Genus Stiphromyrmex , gen. nov. 
Work er. Head rather large, convex above, flattened below, 
with small eyes, situated in front of the middle. Ocelli absent. 
Mandibles rather short, convex, 4-toothed. Maxillary palpi 4-jointed, 
labial palpi apparently 3-jointed. Clypeus bicarinate in the middle, 
short and depressed on the sides. Antennal fovese large, deep and 
circular, not covered by the frontal carinae, which seem to be very 
poorly developed. Antennse 12-jointed, rather robust, with a 3-jointed 
club about as long as the remainder of the funiculus. Thorax very 
short, not longer and decidedly narrower than the head, slightly con- 
stricted on the sides in the mesoepinotal region but without pro- 
mesonotal and mesoepinotal sutures. Epinotum armed with a pair of 
long and powerful spines. Petiole and postpetiole narrow, the former 
with a short, indistinct peduncle, the latter constricted behind Gaster 
subelliptical, somewhat larger than the head, slightly narrowed in 
front, with a very large basal segment. Legs long and robust, the 
femora and tibise clavate; middle and hind tibise with simple spurs. 
Genotype Stigmomyrmex robustus Mayr. 
Stiphromyrmex robustus (Mayr). 
Stigmomyrmex (?) robustus Mayr, Beitr. Naturk. Preuss. I, 1868, p. 97, Taf. V. 
Fig. 101, 
Stigmomyrmex robustus Dalla Torre, Catalog. Hymen. VII, 1893, p. 78; Hand- 
lirsch, Foss. Insekt, 1908, p. 873. 
Worker (Fig. 27). Length about 3,5 mm. 
Head nearly as broad as long, with convex, rounded sides and 
rather deeply excised posterior border. Mandibles short and convex, 
with two blunt, subequal apical and two smaller basal teeth. An- 
tennal scapes curved at the base and reaching about half the distance 
from their insertions to the posterior corners of the head; first funi- 
cular as long as the three succeeding joints together; joints 2 — 7 much 
broader than long, joint 8 nearly as long as broad, terminal as long 
as the two preceding subequal joints. Thorax rounded and convex in 
front, narrower anteriorly, with subparallel sides behind, the latter region 
embracing the epinotum, the former the combined pro- and mesonotum. 
In profile the dorsal outline of the whole thorax to the base of the 
5* 
