AEDES IMPIGER 757 



and revolute, tip pointed and outcurved. Harpagones with a very long stem, 

 its basal and larger portion thick, terminating in a rounded setose knob, apical 

 portion slender, bearing a large terminal filament which is angularly widened 

 in middle, the crest of angulation sharply pointed, slightly recurved. Unci 

 approximated, revolute, forming a thick basal cylinder with a double-pointed tip. 

 Basal appendages approximate, bearing several short stout setae. 



Larva, Stage IV (see figure of the entire larva, plate 73). Head broad, 

 rounded, narrowing slightly before eyes, a slight notch at insertion of antennee, 

 front margin broadly arcuate. Antennge rather long, slightly tapered, densely 

 spined all over with large and small spines ; tuft small, a little before the mid- 

 dle; four short terminal thick spines and one long one. Eyes large, transverse, 

 pointed. Both pairs of dorsal tufts and the ante-antennal tuft multiple. Mental 

 plate broadly triangular, a central tooth and fourteen on each side, becoming 

 larger and more remote basally. Mandible quadrangular, a few spines at base ; 

 two long filaments toward tip; a row of long cilia outwardly from a collar ; four 

 filaments and four very slender ones on outer margin ; dentition of four teeth 

 on a process, the first longest ; a filamentous process before, two little teeth at 

 base, a broad filament and four serrate hairs within ; four little hairs below ; proc- 

 ess cleft-furcate, with tufts of hair; a long angle below; five filamentous hairs 

 within ; a row of long hairs at base. Maxilla conical, divided by a suture ; inner 

 half hairy, a long brush at tip ; outer half with some hair, two filaments near 

 the suture, two spines on the other side ; palpus short, four small terminal digits, 

 one of them short. Thorax rounded, transverse ; hairs rather short and sparse, 

 the subdorsal prothoracic hairs a very small tuft followed by a single long hair. 

 Abdomen rather long, the anterior segments somewhat shorter ; hairs sparse, the 

 laterals of first segment double, the rest single and progressively shorter posteri- 

 orly ; secondary hairs very small ; tracheal tubes broad, band-shaped, slightly 

 expanded in the segments, even and regular. Air-tube stout, tapered, thickest 

 beyond base, about three times as long as wide ; pecten reaching to near middle, 

 the last two or three teeth detached, remote ; a single large tuft beyond pecten. 

 Lateral comb of eighth segment of few scales in a partly double row; single 

 scales with pointed base, the body elliptical and fringed with short spines, the 

 tip a single long, smooth stout spine. Anal segment longer than wide ; dorsal 

 plate reaching very near the ventral line, deeply incised posteriorly; dorsal tuft 

 a brush and rather short hair on either side ; ventral brush well developed, with 

 short tufts preceding barred area toward base; anal gills moderate, ensiform, 

 not very sharply pointed. 



The larvae develop in the early spring pools formed by the melted snow, hatch- 

 ing from overwintering eggs. There is but a single generation in the year. The 

 habits, so far as known, are the same as those of the other early spring species 

 with which they occur, the adults flying in the woods till midsummer. 



Northeastern United States and Canada. 



West Springfield, Massachusetts, April 13, 1905 (Dyar and Knab) ; Long- 

 meadow, Massachusetts, April 16, 1905 (Dyar and Knab) ; Cobble Hill, Eliza- 

 bethtown. New York, larvae April 23, 1905 (H. G. Dyar) ; Karner, New York, 

 March 19, 1904 (E. P. Felt) ; Ottawa, Ontario (J. Fletcher) ; Chats Eapids, 

 Quebec, May 24, 1900 (J. Fletcher) ; White Eiver, Ontario, June 24, 1907 

 (F.Knab). 



We accept Felt's identification of Walker's names as a definite restriction 

 which should be followed. Walker's types being unrecognizable in this group. 

 The European Aedes nigripes (Zetterstedt) has not been critically studied and 

 its relation to our species is therefore unknown. 



