82 MOSQUITOES OF NORTH AMEEICA 



brown. Scutellum trilobate, with vestiture similar to and continuous with that 

 of mesonotum, each lobe with a small tuft of black bristles. Postnotum ellip- 

 tical, prominent, with a broad, low median carina, dark brown, a group of small 

 setae near posterior margin. Pleurse dark brown, coxae luteous, clothed with 

 elliptical, flat, silvery-white scales. 



Abdomen subcylindrical, compressed, truncate apically, and with many long 

 dark-brown terminal setae ; dorsal vestiture black with a slight bronzy and blue 

 reflection ; venter yellowish white ; colors separated at sides in a straight line. 



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

 long as its cell ; that of second posterior cell slightly shorter than its cell ; basal 

 cross-vein distant less than its own length from the anterior cross-vein; out- 

 standing scales of veins ligulate, truncate at tip, black, with bronzy reflection on 

 costa, those on forks of second vein and on apices of third and fourth veins 

 broader and denser. Halteres whitish with black knobs. 



Legs rather long and slender, black with a bronzy and blue reflection ; femora 

 whitish, tibiae brassy beneath; tarsi with bronzy luster below; mid legs with 

 apical portion of second, and all of third, fourth, and fifth tarsal joints white 

 on outer side ; hind tarsi with small white spots at bases of all the joints beneath ; 

 fore tarsi wittiout white markings. Claw formula, 0.0-0.0-0.0. 



Length : Body about 3.5 mm. ; wing 3.7 mm. 



Male. — Proboscis as in the female, with a bronzy shade beneath becoming 

 silvery at base. Palpi much as in the female, very short. Antennae as in the 

 female, the hairs of the whorls somewhat longer and more abundant. Colora- 

 tion as in the female. Wings slightly narrower than in the female, venation and 

 vestiture much the same. Abdomen subcylindrical, expanded at tip, apex with 

 numerous coarse, dark bristles. Middle legs normal, a yellowish-silvery shade 

 beneath throughout, the outer side marked with white, as in the female ; white 

 marks on hind tarsi somewhat longer than in the female. Claw formula, 

 0.0-0.0-0.0. 



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



Genitalia (plate 4, fig. 20) : Side-pieces over twice as long as wide, the tips 

 conically tapered; basal lobes small, roundedly triangular, setose; three long 

 setae in a row; clasp-filament with slender stem, the tip expanded into a cup- 

 shaped clasp of three lobes, the inner slender and smooth, the middle one broad, 

 with truncate, excavated tip, and rows of setae, the outer elliptical, setose on the 

 margin. Harpes concave, the tip curved and obscurely toothed. Harpagones 

 forming a basal cone, the unci another. Basal appendages small, each with two 

 short stout setae. 



Larva, Stage IV (plate 88, fig. 279).— Head rounded, about as long as wide, 

 posterior angles rounded, the sides nearly straight, front margin evenly arcuate. 

 Antennae cylindrical, smooth, a single hair at outer third; two short spines, two 

 very short ones, and a digit at tip. Eyes small, round. Upper pair of dorsal 

 head-hairs in fours, lower pair double. Mental plate wide and shallow, front 

 margm arcuate; a long prominent central tooth and thirteen on each side, even 

 and regular, the basal ones more deeply cut. Mandible quadrangular; a filament 

 from a notch before tip; an outer row of long cilia from a collar; a row of 

 branched filaments before outer margin; dentition of four teeth on a process, 

 the first longest; a short notch before, a broad filament, and five slender ones 

 within; process below remote, taking the place of the basal angle, widely but 

 shortly bifid, with tufts of hair at tips of forks ; a row of fine hairs between it and 

 the dentition ; a row of long hairs within ; a row of long hairs at base. Maxilla 

 elongate elliptical, divided by a suture; inner half with sharp spines along the 

 margin and a median row of cilia; a row of very coarse, thick hairs at tip; outer 



