AQUATIO INSECTS IN NEW YORK STATE 363 



wide as in the male. Anterior tibiae each with one ^pur, 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 bj the brownish cloud. Halteres fuscous, peduncle 

 slightly paler. Length of dried specimens 3.5 to 4.5mm; wing, 

 3.5 to 4.5mm. 



Described from many bred and captured specimens, from Coy 

 glen, Ithaca N. Y., May 1901, and Adirondack mountains, June 

 1901, Moscow, Si>aiilding 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 

 "Ou 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 [pi. 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 

 [pi. 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 ajjical bristles is partly hidden by the 

 Iniir at apex. The maxillae are wider than long; the palpus 

 'rbeing 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.3]. 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 



