1008 MOSQUITOES OP NOETH AMERICA 



branch of second vein; a very conspicuoTis patch of black scales on the costa, 

 involving first vein and origin of second ; distinct patches of black scales at base 

 of third vein and bases of forks of second and fourth veins ; third vein partly 

 whitish scaled ; fifth vein whitish scaled, some black ovate scales towards base, a 

 small black spot at base of fork, another before middle of upper branch and some 

 smaller black scales at tips of both branches ; sixth vein witii a black patch near 

 base and another at apex. Halteres whitish, with black knobs. 



Legs long and slender; femora and tibise with yellowish-white and bronzy- 

 brown scales intermixed, mottled with numerous small spots not forming defined 

 rings; tarsi bronzy-brown, the joints with minute, indistinct yellowish basal 

 rings on two or three proximal joints. Claw formula, 0.0-0.0-0.0. 



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



Male. — Proboscis slender, straight, dark scaled. Palpi about as long as the 

 proboscis, the tip of long joint and last two joints swollen, forming a distinct 

 club and with long, dense pale hairs; vestiture blackish-brown throughout. 

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

 others short, rather stout, whitish; hairs of whorls long, dense, brown with 

 silky yellow luster. Coloration as in the female. Abdomen elongate, depressed, 

 grayish-brown, the apices of the segments darker, an ill-defined, median, longi- 

 tudinal dark stripe inclosing a row of basal elongate median shining black 

 spots. Wing narrower than in the female, the stems of the fork-cells longer, 

 the vestiture less abundant. Claw formula, 2-0.0-0.0. 



Length : Body about 4.5 mm. ; wing 3.5 mm. 



Genitalia (plate 40, fig. 266) : Side-pieces about twice as long as wide, conical, 

 with a stout spine at about middle of inner margin; clasp-filament as long as 

 side-piece, slender, slightly attenuated medianly and bearing a minute stout 

 terminal claw ; at base of side-piece two spines from a common base and a single 

 spine with a rounded tip. Unci slender columnar, with a divaricate tuft of 

 terminal spines. 



Larva, Stage IV. — Head rounded, elongate, longer than wide, bulging at 

 sides, front conically produced; both pairs of dorsal head-hairs single but 

 numerously branched, in a line between the antennae, a smaller hair at base of 

 antenna; two long approximate spines on the front margin. Antennae sub- 

 cylindrical, slightly tapered, spined, one spine near the tuft larger; a tuft of 

 four fine hairs at basal fourth; two long terminal digits with stout spines at 

 their bases and a long, stout, branched hair at tip. Eyes large, normal. Mental 

 plate small, with a median tooth and four on each side ; first side tooth small, 

 second large, fourth small and basally placed. Mandible quadrangular ; a row of 

 long branched hairs at base followed by two feathered filaments ; five filaments 

 before tip, with some fine hairs between them and the outer row of cilia ; a row of 

 small feathered filaments on outer margin; dentition of five teeth on a slight 

 prominence, first and third longest; two serrate filaments within ; a square promi- 

 nence below, composed of confluent spines ; basal angle with a small tuft ; a row 

 of long hairs at base. Maxilla quadrangular, slightly obliquely cut on inner 

 side ; outer edge serrate, front margin broadly covered with bent hairs ; palpus 

 large, exceeding the maxilla, its base roundedly prominent, a dendritic tuft at 

 outer third, a group of irregularly shaped digits at tip. Thorax rounded sub- 

 quadrate, about as long as wide; hairs short, consisting of branched hairs, single 

 hairs and tufts; mesothorax sparsely haired. Abdomen stout, anterior seg- 

 ments shorter; long feathered lateral hairs on first three segments, double on 

 first and second, single on third ; posterior hairs small, smooth ; a dorsal series of 

 five pairs of fan-shaped tufts on third to seventh segments (plate 130, fig. 455). 

 Air-tube sessile, subquadrate, roundedly angled posteriorly. Lateral plates of the 

 eighth segment posteriorly with a series of spines of irregular lengths, the long 

 ones very long, the short ones one-fourth their length. Anal segment about as 

 long as wide, with a small dorsal plate ; dorsal brush a long and a short brush on 

 each side ; a single long lateral hair below the plate ; ventral brush well developed, 



