86 Psyche [March-June 
the apical finger of the pygidial valves twisted inward. In all 
the others (male of rujus not in collection) the valve ends in a 
continuous thin blade-like triangle or hook. 
Hilara cavernicola, n.sp. 
Length 2.25 mm. Testaceo-fuscous, head and genitalia be- 
coming fuscous; all bristles short. Front of female twice as long 
as wide, of male two and one-half times, middle frontal seta 
minute, face as wide as front, gray-dusted, occipital row of 
brownish hairs inconspicuous, ocellar bristles shorter than style; 
basal joints of antennae yellowish, third joint brown, triangular, 
scarcely longer than deep, style slightly longer than third joint; 
proboscis brown, palpi yellow, with a single small pale seta and 
a few small hairs. Thorax dusted with concolorous pollen, not 
vittate, pleurae concolorous with dorsum, dorsocentrals uni- 
seriate, about ten in number and similar to the acrostichals 
which are in four rows with about eight to the inside row, four 
scutellars. Abdomen of male with yellowish incisures, of female 
wholly fuscous, hairs sparse, short and pale, pygidium about the 
size of the fifth segment, the valves with hook-like process at 
anterior apex. Legs without bristles, slender in all parts, coxae 
and legs pale yellow, becoming slightly darker distally where 
the ends of the tarsi may be light brown, tibiae almost equal in 
length to tarsi which are simple and slender, the metatarsi about 
equal to the two following joints. Wings hyaline, stigma very 
faint, veins very thin and light brownish, sections of third vein 
proportioned 1:7:5, of fourth vein 1:4:6, of fifth vein equal; 
halteres pale yellow, alulae and fringe pale. 
Over one hundred specimens mounted, from Lucerne, Lake 
Chelan, Washington, 29 July 1919. 
Most of the species of Hilara are characterized by their males 
having enlarged front metatarsi. In Europe there are only some 
half-dozen species which have slender tarsi, and in the United 
States but one, H. johnsoni. The discovery of an additional 
species which has probably reverted to this generalized condi- 
tion therefore carries unusual interest. Nearly all the species of 
Hilara frequent open water, over which they weave their aerial 
dance. The present species was found swarming in an aban- 
doned mine, evidently attracted there by the enclosed darkness 
rather than by any dampness. 
