AQUATIO INSECTS IN NEW YORK STATE 363 
wide as in the male. Anterior tibiae each with one spur, middle 
and hind tibiae each with a pair. The tarsal claws are simple;, 
wings as in the male, though the media and anal veins are un- 
accompanied by the brownish cloud. Halteres fuscous, peduncle 
slightly paler. Length of dried specimens 3.5 to 4.5mm; wing, 
3.9 to 4.5mm. 
Described from many bred and captured specimens, from Coy 
glen, Ithaca N. Y., May 1901, and Adirondack mountains, June 
1901, Moscow, Spaulding and Peck, Id.; from Professor Aldrich. 
I have compared this with European specimens, and find that 
they agree in every particular excepting that the foreign speci- 
mens I have are a little smaller. A number of female specimens 
collected by Messrs McGillivray and Houghton on Mt Seward in 
the Adirondacks, agree perfectly even in size with those from 
Europe. According to the testimony of the gentlemen named, 
these flies are most "persistent biters. Those found around 
Ithaca are known to annoy horses, and also have been caught 
biting human beings. 
Larvae. In this State they are found in the latter part of 
April and the first two weeks of May; most of them pupating 
before the middle of May; the adults appearing eight or nine 
days after pupation. Some adults appear as early as May 1. 
The head of the larva is quadrangular, of a rich brown color, 
the posterior margin nearly black, with a black, divided eye spot 
on each side. The antennae are slender, first joint occupies 
about two thirds the whole length, the third joint being pointed, 
-and but little longer than wide [pl. 34, fig.5]. The fans have 30 
to 50 scythe-shaped rays, each with a row of fine cilia on the 
inner side, at regular intervals with a longer and stouter seta 
[pl. 34, fig. 8]. The mandibles are stout, with the usual teeth, 
the apical ones being black, the others paler. The large one 
most remote from the apex is not so differentiated as with other 
species. The pair of apical bristles is partly hidden by the 
hair at apex. The maxillae are wider than long; the palpus 
being only about twice as long as broad. At the base of the 
palpus is a tuft of fine setae, and covering it are a few slender 
bristles [pl.34, fig.38]. The labium has seven apical teeth, all but 
the outer ones being trifid; on its ventral surface are two rows 
of five bristles each [pl.34, fig.4]. The labium and hypopharynx 
as in the other species. The dorsal surface of the thoracic 
segments is of a dirty yellow color, the ventral surface is nearly 
