180 
Psyche 
[June-Septernber 
below the level of the clypeus only in darlingtoni, saucius and 
schmitti. In none of these, however, is the front so narrow as in 
mayri, nor is it at all Y-shaped. The back of the head in full dorsal 
view is broadly and shallowly concave in most Ephebomyrmex 
species, but is only excavated to such a degree that it has definite 
occipital lobes in the majors of some subgenus Pogonomyrmex 
species, e.g., badius. The cephalic index approaches that of mayri 
only in cunicularius (84), an undetermined species near cunicularius 3 4 
(84, 87), odoratus (85-87), and angustus (86-89). Only in the latter is 
the occiput at all concave. In some species the sculpture is flattened 
at the edge of the eye, but only in darlingtoni does it become at all 
impressed, and then it is shallow, only weakly defined, and limited 
to the dorsal half of the eye. All species examined have much larger 
eyes, relative to the size of the head, than mayri. The petiolar node 
in most Pogonomyrmex species is well rounded on top, sides and 
apex, and has a distinct posterior peduncle. A few species have a 
broad subacute to acute apex, but only in the sp. near cunicularius 
does the node even superficially resemble that of mayri. On closer 
examination, it also is quite distinct. Sculpture in the subgenus 
Ephebomyrmex tends to be “coarsely rugo-reticulate” (Cole 1968: 
35), but no species examined has the overlying broken, undulate 
pattern of mayri. 
Ergatogyny has occasionally been reported in Pogonomyrmex, 
but most specimens are only occasional aberrations in species with 
normal queens, e.g., comanche, maricopa, subnitidus, calif ornicus 
(Cole 1968: 175), and pima (MCZ). Only one female has been 
reported for cunicularius, and it is ergatoid (Santschi, 1931), but the 
description indicates nothing more remarkable about it than a more 
or less distinct scutellum. Ergatogyny seems to be the rule in 
laticeps. Kusnezov (1951: 273-275) describes the range of ergatoid 
forms, but makes no mention of enlarged waists or gasters, or of 
reduced heads. Those characters are evidently unique to mayri. 
The bizarre form of the P. mayri male is also apparently 
unequalled in this genus (Cole, 1968; Creighton, 1952; Gallardo, 
1932; Kusnezov, 1949, 1951). Some males of Aphaenogaster species 
have elongate heads constricted behind. In the other Pogonomyrmex 
3 Two specimens collected by W. L. Brown in Argentina: Catarnarca, Cat. (airport), 
4 Feb. 1967; Prov. Tucurnan, Krn 1333, Rte. 9, N. of Tapia, 25 Jan. 1967, bosque 
chaqueno. 
