258 
NORTH A^IERICAN MYRMOSIDAE 
shaped or square notch at tip (figures 36 and 47), and in one species 
(crassa) with the entire apical portion bent sharply upwards and 
bifid (figures 21 and 22, A). The sagittae are in the mass of 
species blade-like, slender, and nearly as long as the uncus (figures 
39, 40, and 43 to 49, C), but in those of the castanea group are short 
and of various forms (figures 21 to 30, C), in one case (stygia) with 
their apices much thickened, tricuspid and truncate (figure 25, C). 
What I suppose represent the volsellae are always reduced to a 
pair of small chitinous buttons at the base of and just exterior to 
the sagittae (figures 21 to 31 and 40, D). The rami are roughly 
quadrate pieces (figure 21, E), bearing the long hirsute sciuamae 
(figure 21, B). Their upper posterior angle, as seen from the side, 
is sometimes acutely produced (figure 34), sometimes rounded 
and rolled inward or recessive (figure 48). A piece on either side 
attached both to the lower part of the ramus and the base of 
the sagitta within, I have termed the inner side of the ramus. 
It usually bears a brush of bristles. The squamae are long or 
short, pointed at tip, and sometimes with a distinctly differen- 
tiated posterior margin (compare figures 35 and 39), which in 
three species is deeply notched (figures 21, 24 and 27). This 
notch is usually apparent externally without dissection. 
The genitalia of the iNIutillidae are of a veiy different type 
from those of Brachycistis, especially as concerns the uncus, which 
in the former, if I am correct in my correlation of parts, is a paired 
organ, the penis-zapfen of Zander or crochets of Radoszkowski. 
The probable correspondence of the terms used by the latter 
author for iVIutillidae,^ with those used in this paper for Brachy- 
cistis are indicated in the explanation of the plates on page 289. 
Type of the genus: Brachycistis petiolatiis Fox, by designation 
of Ashmead, 1903. 
A Key to the Suegenera of Brachycistis 
Forewings with three submarginal and three discoidal cells (figure 5), or in 
one species with two submarginal and two discoidal cells (figure 20). 
Brachycistis Fox 
Forewings with only one submarginal and two discoidal cells (figure 50). 
Brachycistellus Baker 
■‘Revision des armures copulatrices des males de la famille de Mutillides. 
Par le General Radoszkowski. Horae Societas entomologica Rossicae. 1885. 
19: 3-44. pi. 1-IX. 
