110 
Psyche 
[September 
colored and are shaped like crooknecked squashes., the 
smaller crooked portion ending in a very small head. The 
length of the full-grown larva, not including the portion 
turned back is about one-fourth of an inch” (p. 3). Fig. 
ID, larva in side view. 
Pogonomyrmex occidentalis (Cresson) 
(PL 11, figs. 1-13) 
Stout; diameter nearly uniform throughout but with the 
thorax somewhat attenuated and bent ventrally; no neck; 
posterior end broadly rounded. Anus terminal. Leg, wing 
and gonopod vestiges present. Nine differentiated somites. 
Body hairs moderately numerous, uniformly distributed. 
Of three types: (1) short (0.036-0.08 mm), with the distal 
half finely denticulate and the base stout to slender, uni- 
formly distributed; (2) long (about 0.27 mm) hairs with 
the distal half finely denticulate; a few in a single row 
around the middle of each somite and also on the venter 
of the prothorax and of the last abdominal somite; (3) 
smooth and long (0.18-0.35 mm), with slender base and 
long flexible tip, restricted to the ventral surface. Cranium 
transversely subelliptical, somewhat broader than long. 
Antennae small slightly raised discs, each with three sen- 
silla, each of which bears a short stout spinule. Head hairs 
moderately numerous, short, to long (0.045-0.11 mm), 
sparsely denticulate on the distal half. Labrum small and 
short (breadth 2X length), bilobed, somewhat narrowed 
ventrally; anterior surface of each lobe with three minute 
hairs, an isolated sensillum near the middle and a pair of 
contiguous sensilla near the ventral border ; ventral border 
of each lobe with spinules and a pair of contiguous sensilla ; 
posterior surface of each lobe with three or four isolated 
and one or two sets of two or three sensilla each and a few 
coarse and mostly isolated spinules. Mandibles robust, 
heavily sclerotized ; apical tooth long, tapering only slightly 
to a rounded point; the two medial teeth are shorter but 
still quite long, subequal and round-pointed. Maxillae with 
the apex paraboloidal and spinulose, the spinules coarse 
and isolated; palp paxilliform with two apical, two sub- 
apical and one lateral sensilla; galea paxilliform, shorter 
than palp, with two apical sensilla. Labium with the 
