274 
NORTH AMERICAN MYRMOSIDAE 
Sagitta l)lade-like, but short and l)liuit; produced externally along the 
middle; volsella a corn])ressed disc; ramus nearly quadrangular, its posterior 
edge almost straight, its superior hind angle not at all produced; the inner 
surface with a brush of bristles; squama short and wide, its posterior margin 
entire; uncus as seen from the side straight and tajiering bluntly to the apex, 
from above keeled in the middle, sloping steeply to the nearly parallel side, tip 
deeply but narrowl}' notched (figures 35, 36, and 37). 
Type material. — Holotype: Las Vegas, Nevada, September 17, 
1908, (the author), [Cornell University, No. 122.1], Paratype: 
Nevada, [American Entomological Society]. 
This species is allied to both aequaUs and idiotes, which have 
each an elongate marginal cell, and would possibly go along with 
noctivaga into Andre’s genus Milluta if this genus were recognized, 
were it not for their simple tarsal claws. The sculpture of the 
mesopleura, forehead and propotleum abundantly distinguish 
noctivaga from any other. 
Brachycistis (Brachycistis) thermarum new species 
cf. Brownish orange; legs and antennae yellowish orange; clothed with 
sparse, slightly yellowish pubescence; the wings hyaline, with pale yellow 
veins and stigma. Length, 10 mm. 
Head ])olished, shining, with punctures irregularly and sparsely scattered; 
ocelli large, moderately prominent, with a deep, impressed, transverse line 
behind them, but no longitudinal line between; measurements: .2,S mm., 
3 mm., .38 mm.; forehead above the base of the antennae with four tubercles; 
inferior margins of the antennal sockets somewhat incrassate, with a small 
tubercle projecting dowmvards; clypeus slightly raised to a median ante- 
marginal point or small tubercle, from there sloping to the shallowly emargin- 
ate edge; mandible with its inner two teeth equal in size, acute, a carina ex- 
tending from the inner toward but disappearing before the base of the mandible; 
gular orifice small, its edge removed from the eye by more than the length of 
the last segment of the labial palpus, and from the swelling at the l)ase of the 
condyle of the mandible by more than twice the apparent width of the same. 
Antennae strongly cremdate, especially toward their apices. 
Pronotum with ])rominent humeral angles, its surface coarsely and closely 
punctate, the punctures a- little sparser on the low'er part of the sides; meso- 
notum bearing coarse, only moderately sparse punctures, and distinct lateral 
grooves; scutellum with coarse and sparse punctures, its sides with a few' 
closer punctures and some minute punctidations; postscutellum closely 
minutely punctvdate, with also tw'O or three coarse punctures; mesopleura 
coarsely punctured, the punctures confluent close to the superior border, be- 
coming sparse as they approach the sternum, the surface prominent but only 
slightly irregularly .sw'ollen; dorsal face of the propodeum impunctate, wdth a 
median longitudinal impressed channel, separated from the posterior face by a 
transverse carina; the lateral angles prominent, wdth a few' coarse punctures,. 
