CULEX ATRATUS 389 



lector to identify it. The swollen proboscis in the $ is also a marked character; so 

 also are the swollen apices of the tibise. Dr. Grabham states that it is the usual 

 swamp form. " I strongly suspect," he says, " the male sucks blood, but have not 

 made definite observations yet." (Sign attached to label X.) Taken by Dr. Grab- 

 ham (who appends the following note) at Ferry Swamp, in the larval stage; " from 

 stagnant algae-containing permanent pools. The larvae feed on algae." 



In a recent letter Dr. Grabham writes: " The small swamp form, a terrible pest in 

 local mangrove swamps; the minnows do not seem to destroy this species." 



Description of Female, Male, and Larva of Culex atratus : 



Female. Proboscis slender, moderate, enlarged at tip, labellfe eonically 

 tapered; vestiture black; setse minute, curved, black, those on labellse more 

 prominently outstanding. Palpi short, black, one-fifth as long as the proboscis, 

 with few outstanding seta? at base. Antenna moderate ; joints subequal, rugose, 

 pilose, black, the second joint a little longer than third ; tori subspherical, with a 

 cup-shaped apical excavation, brown ; hairs of whorls moderate, sparse, black. 

 Clypeus triangular, convex, brown, nude. Eyes black. Occiput brown, clothed 

 with black mostly broad, flat scales ; scales on cheeks below dull white, some 

 erect, forked black ones on nape ; a row of black bristles along margins of eyes. 



Prothoracic lobes elliptical, remote dorsally, with a few dark bristles. Meso- 

 notum brown, clothed with rather large and dense uniformly dark-brown, 

 narrow, curved scales; two ill-defined, broad, longitudinal lines formed by 

 coarser suberect scales. Scutellum trilobate, luteous-brown with a few small 

 bro-rni scales on the large mid lobe, each lobe with a group of black bristles. 

 Postnotum elliptical, prominent, luteous, nude. Pleuras and coxas luteous, with 

 rows of brown bristles. 



Abdomen subcylindrical, truncate at tip ; dorsal vestiture black with a slight 

 blue and coppery metallic reflection, a row of small, lateral, basal, segmental, 

 triangular, white patches ; venter black scaled with small whitish bands at bases 

 of segments. 



Wings moderate, hyaline ; petiole of second marginal cell one-third as long as 

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

 twice its own length distant from anterior cross-vein ; scales of veins brown, 

 those on costa with a bronzy and blue luster, outstanding ones on second to 

 fourth veins near tip of wing ovate. Halteres with slender whitish stems and 

 large dark knobs. 



Legs moderate, black scaled with a bronzy reflection ; femora whitish beneath 

 except tips ; knees concolorous. Claw formula, 0.0-0.0-0.0. 



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



Male. Proboscis long and straight, gradually enlarged towards apex, black 

 scaled with a bronzy luster. Palpi slender, apical portion somewhat enlarged, 

 exceeding the proboscis by more than the length of the last joint; last two and 

 end of long joint, densely hairy; vestiture entirely bronzy brown. Antennae 

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

 whitish, with black rings at insertions of hair-whorls; hairs long, dense, dull 

 brown. Coloration similar to the female. Wings slightly narrower than in the 

 female, the stems of the fork-cell longer; vestiture sparse. Abdomen elongate, 

 depressed, somewhat thickened apically; basal, segmental white spots larger, 

 visible from above beyond the first three segments; lateral ciliation coarse, 

 brown, irregular. Claw formula, 1.0-1.0-0.0. 



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



Genitalia (plate 13, fig. 93) : Side-pieces twice as long as wide, stout, eon- 

 ically tapered at tip ; a low subapical prominence bearing a leaf -like appendage, 

 a slender median prominence bearing a central large spine and a smaller lateral 

 one. Clasp-filament moderate, enlarged at base, with a small terminal articu- 



