54 Psyche [April 
Tachydromia enecator Melander. 
Trans. Am. Ent. Soc., xxviii, 226, 2 (1902). 
Length 3} mm. Totally jet black, shining, except that the knees narrowly 
and the metatarsi are piceous, the palpi, antennae and halteres are dull black, 
and the hinder occiput, pectus, metanotum, a narrow vertical stripe on the 
metapleurae, front coxae, and underside of the front femora are provided with 
a light pruinose coating. Outer antennal joint elliptical, arista terminal. 
Humeral swellings of mesonotum large and well marked: no bristles on dise 
of mesonotum, scutellum with four minute bristles. The <@ abdomen 
depressed, less shining apically, the hypopygium small, terminal, somewhat 
triangular in outline, it and the last ventral segment provided with short 
blackish hairs. Wings with two dark cross bands, the second vein appendic- 
ulate in the known specimens. 
But five specimens are known of this species. ‘The two cotypes, 
both females, are from Quebec and Wyoming. ‘They are now located 
in the Wheeler collection at the American Museum of Natural History, 
New York City. I have a male and two females, collected by my 
former student, E. L. Jenne, at Douglas, Alaska, August 2, 1901. 
This is our largest species. 
Tachydromia schwarzii Coquillett. 
Coquillett, Proc. U. S. N. Mus. xviii. 440 (1895). 
Melander, Trans. Am. Ent. Soc. xxviii. 225, fig. 52 (1902). 
Length 2.5 mm. Shining black, the legs yellowish. Occiput and pro- 
pleurae pruinose. Antennae fuscous to black, the outer joint rounded, the 
terminal arista about four times the length of the antenna. Facets of the eyes 
nearly uniform, front narrow. Palpi glistening white to dirty white, elongate 
and slender. Mesonotal dise shining, bristleless, scutellum with four short 
bristles. Hypopygium moderate, rounded, its curved slender appendages 
sometimes exserted. Legs including the coxae dusky yellow, the hind legs 
darkest, the tibiae and tarsi more or less infuseated. Halteres pale yellow. 
Wings slender, rather pointed, crossed by two broad brownish fasciae, leaving 
the base, middle and tip hyaline; the marginal cilia normally short. 
This is a common insect in the West. During the entire summer it 
hurries about in quick little zig-zag runs in search of its small victims, 
curiously probing among grass, stones, sidewalks, houses, in fact it 
can be found almost everywhere in this region. I have seen hundreds 
of living specimens, and have examined nearly a hundred mounted 
individuals from Moscow, Idaho, and Pullman and Wenatchee, Wash- 
ington. The types came from California and Utah. They are 
numbered 3246 and 3247 in the National Museum collection. 
