122 MOSQUITOES or NORTH AMERICA 



elliptical, prominent, dark brown, a group of small setae near posterior margin. 

 Pleurae and coxge 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 metallic reflec- 

 tion; venter yellowish white, the colors separated at the sides in a straight line. 



Wings rather narrow, hyaline; petiole of second marginal cell one-fourth as 

 long as its cell, that of second posterior cell shorter than its cell ; basal cross-vein 

 distant its own length from anterior cross-vein; scales of veins dense, broadly 

 ovate, the tips obliquely subtruncate, brown, with a bronzy reflection on the 

 costa. Halteres whitish with black knobs. 



Legs rather long and slender, black with bronzy and blue reflections, femora 

 pale beneath; tibia and tarsi bright bronzy beneath; mid tarsi with a pale- 

 brassy luster beneath, hind tarsi with fourth and fifth joints silvery white be- 

 neath. Claw formula, 0.0-0.0-0.0. 



Length : Body about 3.5 mm. ; wing 3.3 mm. 



Male. Proboscis with a pale-brassy luster beneath. Palpi as in the female. 

 Antennae similar to those of the female, the joints with a small secondary sub- 

 apical whorl, the basal whorls with longer, more abundant hairs than in the 

 female. Coloration similar to the female. Abdomen subcylindrical, somewhat 

 expanded towards the tip, with numerous terminal bristles, the claspers con- 

 spicuous. Wing narrow, the venation similar to that of the female, the vestiture 

 slightly sparser. Mid tarsi gently arcuate outwardly, with a brilliant brassy 

 luster beneath, second and third joints silvery white on upper side, the last 

 two dark; hind tarsi with the last two joints narrowly silvery beneath, a broad 

 silvery shade at base of second and third joints. Mid tarsi with a single large 

 claw, those of hind tarsi unequal ; formula, 0.0-0-0.0. 



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



Genitalia (plate 6, fig. 36) : Side-pieces over twice as long as wide, strongly 

 tapered to tip, which is small, inner margin narrowly thickened; a subapical 

 slight lobe bearing two moderately long setae, which are conjoined on their 

 basal half. Clasp-filament rather stout, the tip divided into small lobes, the 

 longer one furcate and hairy, the middle one short, with four stout spines, the 

 outer one sharply pointed. Harpes elongate, slender, the tips bent and toothed. 

 Harpagones and unci reduced, small. Basal appendages represented by three 

 or four leaf-like appendages on each side borne on a bridge-shaped chi- 

 tinous bar. 



Type: No. 12703, U. S. Nat. Mus. 



Larva, Stage IV (plate 90, fig. 387). Head subquadrate, anterior margin 

 rounded, hind angles roundedly prominent. Antennae small, uniform, with a 

 small hair near tip, terminal appendages small. Maxillae with a row of teeth 

 within. Lateral abdominal hairs in twos, the other hairs in coarsely stellate 

 tufts. Lateral comb of eighth segment of many spines in a subtriangular patch ; 

 single spine long, a little enlarged at tip, evenly fringed with fine spinules. 

 Air-tube moderate, slightly tapered, about three times as long as wide ; a false 

 pecten of three teeth near the base ; a hair near base and two beyond pecten and 

 four well-separated ones on the dorsal aspect, all rather short and coarse. Anal 

 segment with a large dorsal plate, spinulated at its posterior margin ; dorsal tuft 

 of long hairs ; lateral tuft of two long hairs ; subventral tufts short and stellate. 

 Anal gills rather long, equal, with broadly rounded tips. 



The larvae live in the fluid that collects in the pale flower-sheaths of Calathea 

 discolor. The eggs are laid in the uppermost, just opening, and still dry 

 flower-sheaths, and hatch when moisture accumulates. This moisture is never 

 abundant and is always of a slimy nature. The eggs are laid singly, but in 

 considerable numbers ; they are smooth, elliptical, and black. 



