2G4 
NORTH AMERICAN MYRMOSIDAE 
Head polished, with very few small punctures; ocelli moderately large and 
prominent, with a transverse impressed line behind but none between them; 
their measurements:® .21 mm., .26 mm., .36 mm.; front slightly convex, 
with even surface, neither tuberculate nor carinate; inferior margin of each 
antennal socket somewhat thickened, but without a tubercle; clypeus raised 
to a sharp, median, ai)ical point, the apex rather narrowly emarginate, with 
distinct but* not sharp lateral angles; mandible with large teeth, a strong 
Carina extending basad from the inner one, strongly angularly elevated just 
before the base of the mandible; gular orifice wide, its lateral margins strongly 
produced and reflexed, distant from the eyes by about the length of the last 
segment of the labial palpus or a little less, and by distinctly less than the 
diameter of the swelling at the base of the mandibles. Antennae not crenulate. 
Hunmral angles not evident; pronotum medially rugulose, laterally sjjarsely 
punctured, almost impunctate on the lower part; mesonotum anteriorly with 
more than the usual number of small setigerous punctures, posteriorly almost 
impunctate, polished; scutellum polished, with few' dorsal punctures and nu- 
merous minute lateral punctulations; post-scutellum w'itli three or four dorsal 
punctures and a few lateral punctulations; mesopleura polished, wuth scat- 
tered punctures, wduch become obsolete ventrally and posteriorly, the surface 
strongly convex Init not irregular, with a pit near the posterior margin; pro- 
podeum dorsally neither sculptured nor polished, without a transverse apical 
Carina, the hind angles rounded, not prominent, the posterior face strongly 
declivous, roughened by the insertion of numerous hairs, as are also the upper 
parts of the sides. 
Wings as shown in figure 18. 
The anterior metatarsi and the middle and posterior tibiae are without the 
noticeable spines found in some species. 
Petiole rather strongly nodose, constricted from the second segment, moder- 
ately long, with a distinct anterior neck, its sides roughened by the insertion of 
numerous erect hairs; pygidium notched, immargined, with a few' poorly de- 
fined lateral punctures. 
Sagitta slender, and tapered, its apex bent upw'ard; volsella reduced to a 
scarcely noticeable button; superior hind angles of the ramus rounded, re- 
ceding; inner side of the ramus with a brush of setae; squama rather short and 
thick; uncus as seen from the side w'idening to the apex, from above strongly 
compressed, w'ithout a flaring apical portion, the apex not notched (figure 4.5). 
Type . — Jemez Springs, New Mexico, May 29, 1913, (Mr. John 
Woodgate), [Cornell University, No. 117.1]. 
Brachycistis (Brachycistis) triangularis Fox, cf • 
Genitalia: Sagitta long, slender and blade-like, ending a little before the tip 
of the uncus; volsella reduced to small chitinized button; squama rather stout, 
its posterior margin entire; uncus slender, slightly widened before and notched 
at the tip, somew'hat decurved (figures 46 and 47). 
®Given always in the follow'ing order: narrower diameter of the posterior 
ocelli, their distance from the compound eyes, their distance from each other. 
