292 MOSQTJITOES OP NORTH AMEBICA 



dant, rather coarse and short, blackish, tip of abdomen very hairy. Claw 

 formula, 1.1-1.1-0.0. 



Length : Body about 5.5 mm. ; wing 4 mm. 



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

 conically tapered ; inner lobe near the middle, quadrate, bearing two stout fila- 

 ments with rounded tips and four setae, the setae arising from a slightly higher 

 part of the lobe ; clasp-filament moderate, slightly enlarged at base, bearing a 

 terminal claw. Harpes divided, inner limb produced into a spatulate tip fringed 

 with teeth, outer limb forming a rounded angle at the base. Harpagones elon- 

 gate, broad, with rounded tips bearing small denticles. Basal lobes small, 

 nearly spherical, bearing a few small hairs. 



Larva, Stage lY (plate 110, fig. 370) . — Head rounded, widest through eyes, 

 a large notch at insertion of antennae, front margin arcuate. Antennae large, 

 slightly curved, thick and spined on basal two-thirds, with a large tuft from a 

 notch, apical third slender; two long subapical setae, a long seta, a short one, and 

 a digit at tip. Both pairs of dorsal head-hairs double, ante-antennal tuft 

 multiple. Mental plate triangular, straight on sides ; a large central tooth and 

 eight on each side, basal ones larger and more remote, last one small. Mandible 

 quadrangular; two long filaments, a short one and a tuft of hairs at tip; an 

 outer row of cilia from a collar ; a row of little rounded transverse prominences 

 within outer margin, bearing hair-tufts ; dentition of four teeth on a process, the 

 first the longest ; a spine before, a triangular tooth and a large trifid one at base, 

 a long, smooth, articulated filament and a long row of feathered hairs within; 

 process below long, curved, obscurely furcate, with a transverse and a longitudi- 

 nal row of hairs and a tuft at tip of each limb ; basal angle rather large, the row 

 of long hairs within with slightly enlarged dentate bases ; a dense row of long 

 hairs at base. Maxilla elongate, conical at tip, divided by a suture ; inner half 

 with a row of long spines on the margin, the basal ones feathered ; two rows of 

 cilia ; outer half with two filaments below middle, a row of long hairs at tip 

 running down next to the suture well toward base and a spine on the other side. 

 Palpus small, with four irregular terminal digits, one which is rather long. 

 Thorax rounded, wider than long; abdomen moderate, the anterior segments 

 shorter ; skin pilose ; tracheae narrow ; lateral hairs multiple on first abdominal 

 segment, triple on second, double on third to sixth. Air-tube long, straight, only 

 slightly tapered, eleven times as long as wide; peeten running to one-fifth, 

 outer teeth rather sparsely spaced ; single teeth flat and broad, with a long basal 

 branch and three or four subapical ones ; a row of five little tufts along posterior 

 margin. Lateral comb of eighth segment of many spines in a large triangular 

 patch ; single spine elongate, widened at tip, fringed with spinules. Anal seg- 

 ment a little longer than wide, ringed by the plate; dorsal tuft a group of long 

 hairs on each side; a single lateral hair; ventral brush weU developed, confined 

 to the barred area. Anal gUls twice as long as the segment, evenly tapered. 



The larvae live in pools in rocky stream-beds. Mr. Knab obtained them in 

 water-holes in a stream-bed, the water clear and in some cases the stream over- 

 hung by high banks, so that the light was dim. In one case the water was milky 

 from soap-suds used in washing. The larvae were difficult to rear, Mr. Knab 

 having failed to get any adults on his first visit to the locality, and only suc- 

 ceeded on his second visit, three years later. The adults probably do not bite. 



Mexico. 



C6rdoba, larvae in a water-hole in the bed of a small stream with perpendicular 

 walls, June 13, 1905, associated with Anopheles strigimacula and Anoplieles 

 eiseni (F. Knab) ; C6rdoba, larvae in a water-hole of some size in a stream-bed, 

 January 6, 1908, associated with Anopheles psetidopunctipennis. Anopheles 



