660 MOSQUITOES OF NOKTH AMEEICA 



Legs moderate; femora clothed with pale yellowish grey scales intermixed 

 with a few black ones which predominate dorsally, a few pure white ones on 

 under side, extreme tips white ; tibiae with pale yellowish grey and black scales 

 intermixed, the pale ones predominating on inner side, a broad black apical 

 ring and a very narrow white basal spot, the stout erect setae dark brown ; tarsi 

 black, each joint of hind tarsi with a very broad, pure white basal ring, the first 

 joint also with a broad median area of pale yellowish grey scales, last joint 

 entirely white; front and mid tarsi with the first three joints white marked at 

 base, a sprinkling of yellowish grey scales at middle of first joints, last two 

 joints of front tarsi black, last joint of mid tarsi nearly wholly white. Claw 

 formula, 1.1-1.1-1.1. 



Length : Body about 4.5 mm. ; wiag 4 mm. 



Male. — ^Proboscis straight, long and slender. Palpi exceeding the proboscis 

 by nearly the length of the last joint, last two joints decidedly inflated ; vestiture 

 of black scales, a narrow white ring near middle of long joint and at bases of 

 last two joints; end of long joint and last two joints with long dense hairs, 

 black on end of long joint, largely pale yellow on terminal joints. Antennae 

 plumose, the last two joints long and slender, rugose, pilose, the others short, 

 dull luteous, with a very narrow black ring at bases of hair- whorls; hairs of 

 whorls long, brownish-black. Coloration similar to the female, the proboscis 

 without white ring. Wings narrower than in the female, stems of the fork-cells 

 longer but not as long as the cells; vestiture sparse. Abdomen elongate, de- 

 pressed, with dense long pale yellow lateral ciliation. Claw formula, 2.1-3.1-1.1. 



Length : Body about 5 mm. ; wing 4 mm. 



Genitalia (plate 31, fig. 211) : Side-pieces over twice as long as broad, apical 

 lobes absent, basal lobe small, conical, densely setose. Clasp-filament long and 

 slender, slightly swollen before middle, with a long, articulated terminal spine. 

 Harpes flat, concave, inner margin thickened and revolute, tip forming a small 

 outcurved point. Harpagones with a slender, columnar stem nearly as long as 

 harpes and a long slender ligulate articulated filament at apex. Unci approxi- 

 mate, obscure, forming a short, rounded-tipped cylinder. Basal appendages 

 rudimentary, bearing a few short setae. 



Larva, Stage IV (see figure of entire larva, plate 63) . — ^Head rounded, promi- 

 nent on the sides, narrowed before eyes, front margin arcuate. Antennae small, 

 subcylindrical, sparsely spined; tuft short and of few hairs, before middle; 

 one longer and three shorter spines at tip and a stout digit on a pedestal. Eyes 

 large, transverse, pointed. Both pairs of dorsal head-hairs single, rather long; 

 ante-antennal tuft multiple, short. Mental plate triangular, wide, apical tooth 

 stout, with eleven teeth on each side about alike. Mandible quadrangular, the 

 tip pointed; two filaments before the collar with a row of cilia outwardly; eight 

 filaments and three plumose hairs on outer edge; a lump and several oblique 

 teeth before dentition, which is of four teeth scarcely raised, the first the largest, 

 a broad filament and three feathered hairs within; process below furcate, with 

 hair-patches; some hair within basal angle; six stout hairs at base. Maxilla 

 hemispherical, divided by a suture ; both halves irregularly and sparsely haired, 

 a tuft of hairs at tip ; outer half with two filaments toward the suture ; palpus 

 constricted centrally, with four terminal digits, of which one is rather long. 

 Thorax rounded, wider than long, robust; hairs abundant, short, subdorsal pro- 

 thoracic ones single. Abdomen rather stout, posterior segments more elongate; 

 hairs short, the lateral ones multiple on first two segments, double on third to 

 sixth ; secondary hairs short. Tracheal tubes broad, band-shaped, slightly con- 

 stricted in the segmental incisures. Air-tube stout, tapered outwardly, twice as 

 long as wide; pecten reaching over halfway, the teeth evenly and closely set; 

 single tooth a long spine with wide base and three rounded branches ; a tuft at 



