1973 ] 
Wheeler & Wheeler — Ant Larvae 
73 
simple or bifid. Labrum with eight hairs on the anterior surface; 
posterior surface with eight sensilla. Each mandible with the blade 
narrow and bearing two teeth. Each maxillary palp a cluster of 
four sensilla. Each labial palp a cluster of five sensilla. 
very young larva. Length (through spiracles) about 1.3 mm. 
Similar to very young larva of L. ambiguus (1955: 23) in shape, 
otherwise similar to mature larva above except as follows. Cranium 
more rounded. Head hairs 0.013-0.038 mm long, all simple. Labrum 
more narrowed ventrally. Mandibles with narrower blade and 
sharper teeth. Maxillae very small ; each galea a slight elevation with 
two sensilla. 
Material studied: 15 larvae from Oregon, G. C. and J. Wheeler 
# 14. 
Leptothorax (Mychothorax) provancheri Emery 
(Fig. 1) 
Length (through spiracles) about 3.7 mm. Paraponeriform (i.e., 
shaped somewhat like a crookneck squash ; neck short and stout ; body 
elongate, stouter, straight and subcylindrical) ; posterior end rounded; 
a ventrally projecting boss on each lateral surface of T r; each thoracic 
somite and AI-AIII with a hairless midventral boss. Anus postero- 
ventral. Leg, wing and gonopod vestiges present. Diameter of spira- 
cles decreasing posteriorly. Integument of posterior somites with 
minute spinules in short rows dorsally and isolated ventrally. Body 
hairs rather sparse. Of three types: (1) 0.025-0.45 mm long, with 
straight or kinked shaft and branched (bifid to dendritic) all branches 
with denticulate tip, on all surfaces of all somites except venter of 
Ti; (2) 0.025-0.1 mm long, simple, on all surfaces of Ti, fewer 
on T2 and T3; (3) 0.25-0.375 mm long, anchor-tipped, with curled 
to kinked shaft, four in a row across the dorsum of each AI-AV 
(sometimes also one on AVI). Cranium subhexagonal, longer than 
broad ; sides of head nearly straight. Each antenna on a teardrop- 
shaped base; each a slight dome with three sensilla, each of which 
bears a spinule. Head hairs numerous, minute (0.003-0.019 mm 
long). Labrum paraboloidal in anterior view; anterior surface with 
12 hairs (about 0.012 mm long), and two sensilla; ventral border 
with two isolated and two clusters of three sensilla each; posterior 
surface with about eight sensilla and a few minute spinules in short 
rows. Mandibles leptothoraciform (i.e., moderately narrow; taper- 
ing gradually and curving gradually to an apical tooth; anterior 
surface produced medially into a blade bearing two subapical teeth) ; 
all teeth subequal. Each maxilla with the apex conoidal ; each palp 
