74 MOSQUITOES OF NORTH AMERICA 



small setae near the posterior margin. Pleurae and coxse luteous, clothed with 

 elliptical, flat, silvery-white scales. 



Abdomen subcylindrical, compressed on basal half, 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-third 

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

 vein distant much less than its own length from anterior cross-vein; scales of 

 veins dense, short, broadly oval, black, with a slight bronzy reflection on costa, 

 denser apically, especially on second and third veins. Halteres whitish, with 

 black knobs. 



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

 beneath ; tibiae and tarsi with a pale bronzy luster beneath ; hind tarsi with basal 

 three-fourths of fourth and all of fifth joints white beneath; scales at base of 

 hind tarsi slightly roughened. Claw formula, 0.0-0.0-0.0. 



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



Male. Proboscis and palpi as in the female ; antennas also similar, the joints 

 elongate, cylindrical, slender, slightly thickened at insertions of whorls, hairs 

 longer and more abundant than in the female, the last joint about equal to the 

 preceding one, slightly thickened, very coarsely pilose. Coloration as in the 

 female. Wings narrower than in the female, the vestiture sparser, cross-veins 

 incident. Middle legs with a silvery luster throughout on the under side ; hind 

 legs marked as in the female. Claw formula, 0.0-0.0-0.0. 



Length : Body about 4 mm.; wing 3.5 mm. 



Genitalia (plate 5, fig. 31) : Side-pieces stout at base, attenuated at apex, in- 

 sertion of clasp-filament indistinct ; three long hairs towards base ; basal lobes 

 setose; clasp-filament slender, long, a spine at basal third, a prominence at outer 

 third, tip very slender, twice angled, pointed, with small spines at first angle. 

 Harpes broad, inner edge thickened, curving at tip and ending in a few teeth. 

 Harpagones forming a basal cone. Unci forming a cone similar to the harpa- 

 gones, but smaller. Basal appendages low, each bearing five small setae. 



Larva, Stage IV (see figure of entire larva, plate 44). Head rounded, hind- 

 angles roundedly prominent, a thick black margin on foramen, sides slightly 

 arcuate, front margin broadly arcuate, with a slight notch at antennal inser- 

 tion. Antennae moderate, cylindrical, smooth, without hair ; four hairs and an 

 attenuated digit at apex. Eyes small, round. Dorsal head-hairs single, ante- 

 antennal tuft triple. Mental plate triangular; central tooth large, with eleven 

 side teeth, the basal ones more remotely placed. Mandible quadrangular, 

 slightly spinulated at base; a filament before tip; an outer row of cilia from a 

 collar ; a dense row of ten divided filaments on outer margin ; dentition of four 

 teeth on a process, the outer long; a broad filament and five feathered hairs 

 with tufted tips within ; process below long, but projecting only slightly beyond 

 the basal articulation, tip widely but shortly furcate, with long tufts at end of 

 each limb and a row of hairs on outer margin; no basal angle, the inner and 

 basal long hairs nearly continuous. Maxilla irregularly hemispherical, divided 

 by a suture ; inner half large, with a row of coarse teeth on margin and a line of 

 fine hairs within; a row of long hairs at tip; outer half small, lunate; a single 

 filament next the suture, with cleft tip ; a small spine on the other side. Palpus 

 small, with four minute terminal digits. Thorax rounded quadrangular, much 

 wider than long; hairs abundant, long; short hairs in small tufts. Abdomen 

 slender, segments widening posteriorly; lateral hairs on first two segments 

 multiple, double on third to fifth, single on sixth and seventh; short hairs in 



