106 
Psyche 
[September 
Tribe Myrmicini (F. Smith) 
Stout; diameter greatest at the fourth or fifth abdominal 
somite; slightly attenuated anteriorly; thorax very stout 
(when mature) and arched or bent ventrally, but not dif- 
ferentiated into a neck; posterior end broadly rounded. 
Antennae each with three (rarely two or four) sensilla, 
each of which bears a stout spinule. Head hairs short to 
long; mostly denticulate. Labrum small and short; breadth 
twice the length; bilobed; anterior surface of each lobe 
with 2-5 minute hairs and 1-5 sensilla; posterior surface 
spinulose and with 8-18 sensilla. Mandibles rather small 
or moderate-sized (ratio of head width to mandible length 
2. 1-2.9, average 2.5) ; stout (ratio of length to width at 
base 1.8-2. 4, average 2.1) ; heavily sclerotized; no spinules. 
Apex of maxilla usually spinulose; palp and galea paxilli- 
form, bearing respectively five and two sensilla ; palp slight- 
ly shorter than or equal to galea. Anterior surface of 
labium usually spinulose; palp a low elevation bearing four 
or five sensilla; opening of sericteries a short transverse 
slit (concealed in a groove). Hypopharynx usually sparsely 
spinulose, the spinules minute and generally in transverse 
rows. 
Genus Pogonomyrmex Mayr 
Stout; diameter greatest at the fourth or fifth abdominal 
somite; slightly attenuated anteriorly; thorax very stout 
(when mature) and arched or bent ventrally, but not dif- 
ferentiated into a neck; posterior end broadly rounded; 
anus terminal or subterminal. Body hairs moderately 
numerous; mostly denticulate; anchor-tipped hairs lacking. 
Antennae each with three sensilla, each of which bears a 
stout spinule. Head hairs short to long ; sparsely denticulate 
on the distal half. Labrum small and short; breadth twice 
the length ; bilobed ; anterior surface of each lobe with two 
or three minute hairs and 3-5 sensilla; ventral border of 
each lobe spinulose and bearing two contiguous sensilla; 
posterior surface with a few coarse spinules and numerous 
sensilla. Mandibles with the apex forming a rather long 
and moderately slender tooth which is round-pointed and 
which tapers slightly. 
Wheeler & Bailey, 1920, p. 251 : “Certain agricultural 
