254 
NORTH AMERICAN MYRMOSIDAE 
females of Myrmosa. As to what these females really are, I can 
only suggest that they may represent the female sex of those 
species heretofore included in the genus Myrmosa, but for which 
is established in this paper the subgenus Myrmosula, or, more 
probably, a genus of which the males are as yet entirely unknown. 
The females to which reference has just been made have been 
suspected by Ashmead of belonging to the genus Milluta of Andre. 
That genus was based on a palearctic species unknown to me, 
and may have valid claims for recognition on the basis of other 
characters than those stated. Although some of our species 
possess the chief characters on which this genus is said to be 
based, I can not believe that they form by themselves a section 
worthy of generic or even subgeneric rank. However, none of 
them possess toothed tarsal claws, as in Milluta, and I believe 
the latter genus will have to be restricted to the palearctic species 
on the basis of this distinction, and possibly others, perhaps in the 
genitalia, as jmt unknown. 
The Characters of the Males of Brachycistis 
Most frequent color brownish orange to castaneous, or mahog- 
any red, often with the head black and sometimes wholly black; 
other colors not known. Wings hyaline or slightly infuscated 
beyond the stigma. Length from 6 to 20 mm. The colors seem 
quite constant specifically, the black on the thorax, however, 
sometimes varying to dark red. They are clothed with sparse, 
erect, usually yellowish pubescence, thickest on the pronotum, 
caudal face of the propodeum, sides of the petiole, and abdominal 
segments, where it is arranged in sinuous, closely set, transverse 
rows, one on each segment. 
The head is transverse, more or less narrowed behind the eyes, 
which are very large, bead-like, round, and reach the mandibles. 
Ocelli usually large and prominent, but sometimes small and not 
prominent. Their size and distance from the eyes and from each 
other afford very important specific characters. Under the 
specific description the measurements of the ocelli are given in 
the following order; narrowest diameter of the posterior ocelli, 
distance from the eyes, distance from each other. The anterior 
ocellus is transverse, and often larger than the others; the pos- 
terior are somewhat obliquely placed, and by reason of being 
