75 
1932 ] Female of Acamatus from Texas 
kindly made the necessary examination, writes me as fol- 
lows : 
“I have compared your specimens of Acamatus with the 
types of wheeleri Emery in my collection. They differ from 
these types in having a somewhat shorter head with less 
produced posterior angles and both the head and promeso- 
notum are distinctly smoother and more shining. In the 
typical wheeleri the whole thorax is sculptured and sub- 
opaque. I believe, therefore, that your form may be re- 
garded as a new subspecies or the hereto unknown worker 
of one of the Texan species known only from males.” 
It is much to be regretted that no males were present in 
the colony since their absence reduces any attempt to cor- 
relate this form with a previously described male to pure 
speculation. It had best, therefore, be regarded as a sub- 
species of wheeleri until the time when the discovery of a 
nest containing all the castes will definitely settle the ques- 
tion. In any case the female warrants description since it 
is markedly different from those of the three North Amer- 
ican species of Acamatus in which this caste is known. 
Eciton (Acamatus) wheeleri subsp. dubia subsp. nov. 
Worker : Head shorter than that of the typical wheeleri , 
the posterior angles less produced ; head and promesonotum 
smoother and more shining. Otherwise as in the type. 
Female: (Plate III, figs. 1, 2 and 3.) Length 13.5 mm. 
Head, thorax and petiole 4 mm. Gaster 9.5 mm. 
Head subquadrate, the sides straight and very slightly 
convergent in the anterior half, feebly convex in the pos- 
terior half. Occiput produced behind into two well-marked 
lobes each of which passes ventrally to a blunt but distinct 
angle at the inferior border of the occiput. The middle of 
the occiput with a prominent, rounded, median groove. 
Ocelli absent. Eyes consisting of two or three indistinct, 
unpigmented and depressed facets which lie a little behind 
the middle of the side of the head. Anterior border of the 
clypeus evenly concave. Antennal carinse rather short, the 
anterior portion partially encircling the antennal fossa, the 
posterior part fusing with the front a short distance behind 
the insertion of the antenna. A long, depressed triangular 
area between the carinse extends well back behind the pos- 
