1954] Wheeler and Wheeler — Basicerotini and Dacetini Ant Larvae 117 
Rhopalothrix gravis Mann 
(PL 6, figs. 1-10) 
Immature: Length about 2.8 mm. Somewhat stout; 
thorax and first abdominal somite forming a neck which 
is strongly curved ventrally, remainder of abdomen with 
the dorsal profile curved and the ventral nearly straight; 
posterior end broadly rounded. Anus ventral, with a dis- 
tinct posterior lip. Spiracles rather small. Integument of 
the ventral surface of the thorax and abdominal somites 
I and II with a few short transverse rows of minute spi- 
nules. Body hairs numerous and uniformly distributed, 
except scarce on the ventral surface. Of two types: (1) 
slender, flexible, denticulate, short to moderately long 
(0.09-0.11 mm), without alveolus and articular membrane, 
on the dorsal and lateral surfaces, the more abundant 
type; (2) stout, of nearly uniform diameter, slightly curved, 
with a short sharp apical hook, denticulate, short to long 
(0.09-0.22 mm), with alveolus and articular membrane, 
in a narrow irregular band around the middle of each 
somite. Head moderately large; cranium somewhat broader 
than long, vaguely subhexagonal in anterior view, but with 
the occipital border strongly impressed at the middle; cly- 
peus bulging. Antennae minute, each with three sensilla, 
each of which bears a spinule. Head hairs few, long (0.09- 
0.14 mm), flexible and denticulate. Labrum small, breadth 
twice the length, feebly bilobed; anterior surface of each 
lobe with 4 or 5 minute hairs and/or sensilla; lateral bor- 
ders with isolated coarse spinules; ventral border of each 
lobe with minute spinules in short rows and with one 
isolated and two contiguous sensilla; posterior surface of 
each lobe with two isolated and two contiguous sensilla; 
whole posterior surface spinulose, the spinules minute and 
in numerous rows, the rows transverse on the middle half. 
Mandibles heavily sclerotized, long and slender, slightly 
curved medially; apical tooth long and rather slender; with 
two teeth projecting inward from the inner border (the 
distal small and the proximal large) ; with 3 or 4 denticles 
on the distal half of the posterior surface. Maxillae large; 
each divided into two parts by a transverse lateral impres- 
sion, the basal part swollen laterally and bearing the palp. 
