260 MOSQUITOES OF NORTH AMERICA 



yellowish, narrow, curved scales, each lobe with a tuft of blackish bristles. Post- 

 notoum elliptical, prominent, brownish luteous, nude. Pleurje and coxse luteous, 

 with small patches of white scales and with rows of small brown bristles. 



Abdomen subcylindrical, truncated at tip ; dorsal vestiture black, with a slight 

 greenish-metallic reflection, a row of lateral basal segmental triangular small 

 sordid-whitish spots ; venter yellowish, with indistinct dusky-black apical seg- 

 mental bands, a row of pale hairs at tip of each segment dorsally. 



Wings moderate, hyaline; petiole of second marginal cell about one-half as 

 long as its cell, that of second posterior cell a little shorter than its cell ; basal 

 cross-vein more than its own length distant from anterior cross-vein; scales 

 blacldsh brown, darker costally, with bluish and bronzy reflection, the outstand- 

 ing ones broadly linear, very dense on forks of second vein. Halteres whitish. 



Legs moderate; femora white beneath almost to tips; hind knees narrowly 

 white; tibiae and tarsi brownish black, tips of tibiae white; hind tarsi with very 

 narrow white bands at base and apex of each joint, tip of last joint black; mid 

 tarsi with the two basal joints narrowly white marked at base, front tarsi un- 

 marked. Claw formula, 0.0-0.0-0.0. 



Length : Body about 4 mm. ; wing 4 mm. 



Male. Proboscis slightly enlarged towards tip, black scaled, with a narrow 

 white ring beyond the middle. Palpi exceeding proboscis by nearly the length of 

 last two joints, end of long joint and last two joints with numerous black hairs, 

 faint whitish rings at bases of last two joints and at basal third of long joint. 

 Antennae plumose; last two joints long and slender, rugose, pilose, black, the 

 others short, pale, with black rings at insertion of hair- whorls ; hairs, long, dense, 

 black. Coloration similar to the female. Wings narrower than in the female, 

 the stems of the fork-cells a little longer; vestiture sparse. Abdomen long, 

 depressed, expanded toward apex, with distinct but rather narrow white bands 

 at bases of segments dorsally; lateral ciliation dense, rather long and coarse, 

 brown. Claw formula, 1,1-1.1-0.0. 



Length : Body about 4 mm. ; wing 3 mm. 



Genitalia (plate 16, fig. 119) : Side-pieces over twice as long as wide, coni- 

 cally tapered at tip ; marginal appendages on a subapical truncated prominence 

 consisting of three rods with hooked tips and a leaf-like appendage and a seta. 

 Clasp-filament stout, rather long, curved, with a small articulated appendage. 

 Harpes furcate, lower branch curved, with a rounded tip, outer bearing a dense 

 terminal tuft of spines. Harpagones furcate, inner branch simple, outer divided 

 into several irregular teeth. 



Larva, Stage IV (plate 102, fig. 337). Head rounded, a little wider than 

 long ; antennae rather small, uniform, the tuft at middle, arising from a slight 

 notch; upper head-hairs in fives, lower in sixes, ante-antennal tuft multiple. 

 Lateral hairs of abdomen in sevens on first segment, fours on second, threes on 

 third to fifth, twos on sixth ; subdorsal hairs long and double on fourth to sixth 

 segments. Lateral comb of eighth segment of many spines in a triangular patch. 

 Air-tube about five times as long as wide, subconically tapered outwardly, pecten 

 of short, sparse teeth, reaching the basal two-fifths ; five multiple tufts of long 

 hairs, two of them within the pecten, the subapical one moved laterad out of 

 line, the two towards tip of tube shorter and sparser. Anal segment about as 

 long as broad, ringed by the plate ; dorsal tuft of four hairs of different lengths 

 on each side ; lateral hair small, single ; ventral brush confined by the chitinous 

 ring. Anal gills very large and broad, tracheate, the ends bluntly rounded, 

 about three times as long as anal segment and over half its diameter. 



The larvae occur in crab-holes along the shore, associated with Deinocerites 

 cancer. The adults frequent the upper parts of the holes, coming out to swarm 



