400 MOSQTHTOES OF NORTH AMERICA 



hairs along the posterior borders of the segments. Small lateral white scaled areas 

 on the sixth and seventh segments formed by the extensions of the white ventral 

 bands. Venter with broad crescentic basal bands of silvery scales. Legs black, ventral 

 surfaces of the femora white, except at the extreme apices, where there are patches 

 of black bristles; apices of femora and tibiae swollen. A band of lighter scales 

 running along the under surfaces of all the legs (especially marked on the mid legs) 

 to the tips. A yellow spot at the apex of hind tibiae. Knee spots not defined. Ungues 

 equal and simple. Wings, the apical portions of the first four long veins densely 

 scaled with broad fan-shaped scales. The two median rows of broad scales are rep- 

 resented by narrow elongated ones on the bases of the second and third, first part of 

 the base of the fourth and upper arm of the fifth. The remainder of the base of the 

 fourth and the lower arm of the fifth have long scales on one side only. The base 

 of the fifth has broad scales only throughout its length. On the sixth long vein the 

 scales are all slender and elongated. First submarginal cell as wide as but much 

 longer than the second posterior, about four times as long as the stem; second pos- 

 terior with the stem about half length of the cell. Posterior cross vein about twice 

 its own length distant from the mid cross vein. Halteres with pale stems and knobs, 

 the latter mottled with dark areas. Length, 2.5 mm. 



(J. — Palpi black, copiously speckled with yellowish scales, slender, larger than the 

 proboscis, the tip of the latter reaching to the middle of the penultimate joint; long 

 hairs along the sides and under surfaces of the first two joints and apex of the ante- 

 penultimate joint Both terminal joints and apex of antepenultimate joint slightly 

 swollen. Abdomen black, with scattered dull white scales; these form an ill-defined 

 band down the centre of the abdomen, lateral patches of silvery scales on the fifth, 

 sixth and seventh segments. Legs black, conspicuous lines of lighter scales on the 

 under surfaces of all the legs. Ungues of the fore and mid tarsi unequal and uni- 

 serrate; larger with one long median blunt tooth, smaller with a small basal tooth. 

 Ungues of the hind tarsus equal and simple. Length, 2.5 mm. 



The following points were noted in the adult labva: Pully grown larva about % 

 inch long, with relatively large head and thorax. Antennae large and prominent, 

 larger than the head, slightly curved in lower third, somewhat swollen in the basal 

 half, only moderately infuscated, rather more so above the lateral tuft and at the 

 extreme base. Tuft a little above the middle, of about twelve fine flattened hairs 

 measuring about three-quarters length of the antennal shaft Apex with four large 

 deeply infuscated spines, the two longest about half the length of shaft Surface 

 covered with many fine chitinous spines, especially along the outer aspect Mentum 

 small, with about fifteen teeth, apical tooth prominent. Upper epistomal hair double 

 or single, lower larger, single, both flattened, neither reaching to the anterior border 

 of head. Anteantennal hair with five or six divisions, flattened. Thorax coarsely 

 pilose along the anterior and lateral aspects. Abdomen finely pilose, more densely 

 at the insertion of the lateral hairs and near the comb. Lateral hairs long, five on 

 each side of the first segment, three on the second, paired on the hinder segments. 

 Comb of 10-12 well-separated bars in a curved row, upper ones smaller, smallest 

 about one-third length of longest Each scale has a line of fine hairs on each side, 

 most marked on the swollen basal portion. Air tube subconical, with a slight curve 

 forward, about five times as long as broad (at the base). A pair of hooks at the tip, 

 each with a fine curved tooth at the middle. Eight or nine pairs of long hairs along 

 the posterior surface, each with 4-5 divisions; upper shorter, two pairs within the 

 lines of insertion of the pecten teeth. Lines of pecten teeth insertions reach up one- 

 quarter of the tube; teeth about nine pairs, upper very long, tips of the highest 

 approach the middle of the tube, each tooth narrow, flattened, slightly curved, with 

 many fine setje along its inner border. Two pairs of small compound hairs on each 

 side of the tube, one near the middle, the other within the upper quarter. Band ring- 

 ing the anal segment about as long as broad. Ventral group of hairs spring from a 

 separate barred area. Dorsal group of two pairs of very long simple, nearly equal, 

 hairs. Anal gills with prominent tracheae, elongated, narrow, unequal, lower pair 

 longest, half as long again as the ventral hair group. Pupa with rather long, deeply- 

 Infuscated siphons. 



Observations. — The larvse of this species, belonging to Dyar and Knab's interesting 

 new genus, MocUlostyrax, were collected in the same locality as the preceding. They 

 were placed in a separate jar, with an abundance of Crustacea and Influsoria, and 

 developed rapidly. The usual position of the larva was on its back at the bottom of 

 the jar or hooked up on the sides by its siphon. It apparently never rose to the 

 surface except just before pupating. The adults bear a strong superflcial resemblance 

 to the small swamp mosquito, Melanoconion atratus Thee, the venation and form of 

 the wing scales being precisely similar. The description of the adults was drawn up 

 from freshly-killed specimens. 



