1934 ] 
An Australian Leptothorax 
61 
broadly rounded posterior corners and nearly straight, 
anteriorly converging sides. Eyes rather large and convex, 
situated slightly in front of the middle of the head. Man- 
dibles stout, with convex external borders, the masticatory 
borders with three terminal teeth but with the basal half 
straight and indistinctly crenulate. Clypeus convex, its 
anterior border broadly rounded and entire in the middle, 
sinuate on each side. Frontal carinse thin, rounded, scarcely 
diverging behind ; frontal area distinct, impressed, 
elongate;, frontal groove absent. Antennse stout, 12- 
jointed; scapes strongly curved at the base, their tips reach- 
ing to slightly more than two-thirds the distance between 
their insertions and the posterior border of the head; first 
funicular joint as long as joints 2 and 3 together, 2 nearly 
as long as broad, 3-8 decidedly broader than long, remain- 
ing joints forming a very distinct 3-jointed club, the com- 
bined two subequal basal joints of which are shorter than 
the terminal. Thorax in profile with broadly arcuate dorsal 
outline, but slightly and indistinctly impressed at the 
mesoepinotal suture, broadest through the pronotum; neck 
large, anterior border of pronotum arcuate, its anterior 
angles distinct but neither acute nor dentate, its sides 
straight, parallel and marginate anteriorly, straight and 
converging posteriorly; promesonotal suture obsolete; 
mesonotum short, nearly twice as broad as long, with sub- 
angulate sides and somewhat flattened dorsal surface; 
epinotum longer than broad, subrectangular, slightly nar- 
rower than the mesonotum, its base from above subhexa- 
gonal, with very prominent spiracles, the spines stout and 
blunt, as long as their distance apart at the base, directed 
backward and slightly upward and curved inward; the 
declivity in profile shorter than the base, straight and 
abrupt above, concave below. Petiole more than twice as 
long as broad, its peduncle long and stout, as long as the 
node, with prominent spiracles anteriorly and a sharp an- 
teroventral tooth; the node from above somewhat broader 
than long, subrectangular, with evenly rounded sides; in 
profile with concave anterior, straight and horizontal 
superior and short and convex posterior surface. Post- 
