76 
Psyche 
[June 
debatable point, but it is certainly true that they give to 
the male of huachucanus an appearance which is much 
more like that of a Myrmica male than is usual for a male 
of Pogonomyrmex. It would be interesting to know if the 
male of bispinosus also shows these characteristics. At 
present this caste appears to be known only from Spinola’s 
original description (5) which is too imperfect to be of 
much service. 
There is one more point that may have a bearing on the 
primitive status of huachucanus. As already noted, several 
nests of huachucanus were excavated to determine their 
structure. In particular, two of them were completely 
exposed with all of the passages opened up. I had expected 
to find stores of seeds in these nests but failed to do so. Yet 
this species certainly garners seeds, for one occasionally 
encounters small quantities of chaff on the excavated fans 
at the nest entrance. It seems possible that the harvesting 
habit is poorly developed in huachucanus, it gathers seeds 
but it may fail to store them. If true, this would be a 
further proof of the primitive character of this species. It 
is to be hoped that additional observations will give us more 
light on this point. If nests of huachucanus can be examined 
in the fall, winter and spring and not just during the sum- 
mer months, it should be possible to show the existence of 
stores of seeds if this ant makes them. 
The general features of all three castes of P. huachucanus 
are shown in the figures on Plate 4. The following descrip- 
tions deal mainly with details not shown in the above figures. 
Worker: Length: head (exclusive of the mandibles) 
2.25 mm.; thorax 2.75 mm., overall length 5-5.5 mm. 
The entire upper surface of the head covered with wavy 
longitudinal rugae, those at the middle of the head diverg- 
ing toward the occipital corners. Over most of the upper 
surface of the head the rugae rarely form reticulations but 
on the genae and the posterior quarter of the head they are 
Explanation to Plate 8 
Pogcnomyrmex huachucanus Wheeler. Pig 1. Female. Fig. 2. Worker. 
Fig. 3. Male. Fig. 4 Head of female. Fig. 5. Head of worker. Fig. 6. 
Head of male. 
Figs. 1-3 are drawn to the same scale; figs. 4-6 are drawn to the 
same scale. 
