CULEX IMITATOR 433 



its stem less than one-third the length of the cell; stem of the second posterior cell 

 not quite as long as the cell; posterior cross-vein not quite twice its own length dis- 

 tant from the mid. 



Length. 2.5 mm. 



Habitat. Rio Janeiro (Professor Goeldi). 



Time of capture. April. 



Observations. Described from two $'s and two c5"s. It is a very pretty small 

 species, easily told by the thoracic adornment. The c? palpi differ from Culex 

 proper, and there are some differences in wing scales and in general appearance. 

 This small stout gnat is totally different from any member of that genus. 



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



Female. Proboscis rather long, slender, apical third thickened; labellse 

 conically tapered; vestiture black with a blue reflection towards tip; setae 

 minute, curved black, those on labellae more prominently outstanding. Palpi 

 short, black, one-sixth as long as proboscis, with some outstanding setse at base. 

 Antennae moderate, joints subequal, rugose, pilose, black, second joint scarcely 

 enlarged ; tori subspherical, with a cup-shaped apical excavation, pale yellowish ; 

 hairs of whorls sparse, black and rather short. Clypeus broad, rounded, convex, 

 dark brown. Eyes black. Occiput black, clothed with narrow, curved silvery 

 scales, numerous erect forked yellowish scales ; cheeks clothed with broad, flat, 

 dull white scales ; coarse black bristles along margins of eyes. 



Prothoracic lobes elliptical, remote dorsally, clothed with narrow, curved 

 silvery-white scales and a few black bristles. Mesonotum brown with two nar- 

 row bare impressed lines, vestiture of dense, narrow curved scales, bright shining 

 brown on the disk, very broadly silvery white scaled on the lateral and anterior 

 margins and in a large spot on each side of the middle and joined to the lateral 

 margins, as well as a broad border of silvery scales at the sides of the ante- 

 scutellar space; bristles black, long. Scutellum trilobate, pale, clothed with 

 narrow silvery scales, each lobe with a group of black bristles. Postnotum ellip- 

 tical, luteous brown, nude. Pleurae luteous and whitish, a dark spot beneath 

 wings and a dark band above base of coxae ; small patches of elliptical, flat white 

 scales. 



Abdomen subcylindrical, depressed, truncate at tip, clothed dorsally with 

 black scales with a strong coppery metallic reflection, a series of narrow, white, 

 basal, segmental bands or spots, becoming obsolete towards base and apex or 

 altogether absent ; a row of lateral, white, basal, segmental spots ; venter clothed 

 with yellowish-white scales and with narrow black bands at tips of segments. 



Wings ample, hyaline ; petiole of second marginal cell about half as long as 

 its cell, that of second posterior cell about equal to its cell ; basal cross- vein dis- 

 tant more than its own length from anterior cross-vein ; scales of veins brown, 

 long, linear, not very dense. Halteres white, with a black knob. 



Legs slender, rather long ; femora black above, white beneath nearly to apex, 

 tips silvery white; tibia black above, whitish beneath, a small silvery spot at 

 base and tip above ; tarsi black with basal white rings on the joints, obsolete on 

 the front tarsi, narrow on the median pair and with the last joint all black, 

 broad on the hind tarsi, the fourth joint with the basal half white, the fifth white 

 and its tip black. Claw formula, 0.0-0.0-0.0. 



Length : Body about 2 mm. ; wing 3.5 mm. 



Male. Palpi as long as the proboscis, slender, uniform, the last joint not 

 tapered ; vestiture black with a broad white ring at base of last two joints and at 

 the middle of the long joint, a few short black hairs on last two joints and tip 

 of long joint. Antennae plumose; last two joints long and slender, rugose, 

 pilose, black, the others short, whitish, with a black ring at insertions of hair- 

 whorls ; hairs long, dense, brown. Coloration similar to the female. Abdomen 

 elongate, depressed on apical half, the fifth and sixth segments laterally ex- 



28 



