The Two-winged Flies 
347 
recognize some twenty distinct subfamilies (or families, if the group 
Muscidae be looked on as a super-family) of these small flies, but the distinc¬ 
tions are quite too fine for the general collector to handle. I shall therefore 
simply refer briefly to a few of the more interesting or abundant or economi¬ 
cally important species in this group. 
Fig. 493. —Red-tailed Tachina-fly, Winthemia 4-pustuluta, a parasite of the army-worm, 
Leucania unipuncta. a , fly, natural size; b, fly, enlarged; c, army-worm, natural 
size, upon which eggs have been laid; d, parasitized army-worms, enlarged. (After 
Slingerland.) 
Of interest because of the extraordinary condition of their eyes are the 
blackish flies called Diopsidae, which have the eyes on conspicuous elon¬ 
gate lateral processes of the head. These eye-stalks bear also the antennas. 
Only a single species, Sphyracephala brevicornis, has been found in this 
country, and regarding its life-bdstory nothing is known. The flies are to be 
looked for in woodsy places, and particularly on the leaves of skunk-cabbage. 
In the water and cast up in masses along the shores of Mono Lake and 
certain other similar brackish-water lakes in the desert land just east of 
the Sierra Nevada Mountains in California may be found, at certain seasons 
of the year, innumerable larvae of a small predaceous fly of the genus Ephydra. 
These dead-sea waters support hardly any other animal life, but this fly 
finds the water much to its liking and breeds there with extraordinary fecun¬ 
dity. The Pai Ute Indians of this region, who, like the flies, have a ques¬ 
tionable palate, gather these larvae by the bushel, dry them in the sun, and 
use them for food under the name koo-chah-bee. Prof. Brewer of Yale, 
who made a trial of koo-chah-bee, says “it does not taste badly, and if one 
