596 MOSQUITOES OF NORTH AMERICA 



last two joints and before middle of long joint; end of long joint and last two 

 joints with rather short black bristles. Antennae plumose; last two joints long 

 and pilose, the others short, black at insertions of hair-whorls, paler beyond; 

 hairs of whorls long, dense, blackish brown. Coloration similar to the female. 

 Abdomen elongate, depressed, with abundant, rather coarse, brown lateral 

 ciliation; the narrow white apical segmental bands distinctly divided in the 

 middle, especially posteriorly. Wings narrower than in the female, the stems of 

 the fork-cells longer, the vestiture less abimdant. Claw formula, 1.0-1.0-0.0. 



Length : Body about 5 mm. ; wing 3 mm. 



Genitalia (plate 23, fig. 160) : Side-pieces more than twice as long as wide, 

 conically tapered, the apical lobe imdeveloped, the basal lobe absent; clasp-fila- 

 ment stout, strongly swollen at outer two-thirds with a few minute setse, a short 

 stout articulated terminal spine. Harpes flat, concave, inner margin thickened 

 and revolute, cleft at tip, forming two teeth directed outwardly. Harpagones 

 with a slender Hgulate base and broadly triangular tip bearing six stout setae 

 on elevated bases. Unci contiguous, forming a slender cone. 



Larva, Stage IV (plate 116, fig. 395). — Head rounded, wider than long, nar- 

 rower before eyes, a notch at insertion of antennae, front margin broadly arcuate. 

 Antennae very long, longer than head, subcylindrical, slightly narrower on outer 

 half and a little widened at tip, curved, sparsely spined all over; a large tuft at 

 middle; three long hairs, a short hair, and a digit at tip. Eyes large, trans- 

 verse, pointed. Tipper pair of dorsal head-hairs multiple, lower single; ante- 

 antennal tuft multiple. Mental plate triangular, with a central tooth and 

 thirteen on each side, all much alike, basal ones a little more sparsely placed. 

 Mandible quadrangolar, a filament and three short hairs before tip; an outer 

 row of cilia ; a row of fine hairs from angular prominences on outer margin ; 

 dentition of four teeth on a process, the first larger; a spine before, a large 

 double tooth and a fan-shaped divided one at base, a broad coarsely serrate fila- 

 ment and three feathered hairs within ; process below furcate, with tufts of hair 

 and a line of hairs running basally ; basal angle small ; a row of hairs within and 

 a row at base. Maxilla elongate, tip conical, divided by a band-shaped suture ; 

 inner half with lines of stiff cilia ; a tuft of long hairs at tip; outer half with a 

 single articulated filament next the suture near the middle and a small subapical 

 spine on the other side. Palpus short, thick, with a long apical digit and three 

 short ones. Thorax rounded, wider than long; hairs abimdant but not long. 

 Abdomen moderate, the anterior segments shorter; lateral hairs of first two 

 segments multiple, small and double on following segments. Tracheal tubes 

 broad, band-shaped, expanding in tube. Air-tube large, inflated, tapered on 

 outer half, three times as long as wide; pecten of five or six teeth scattered over 

 basal half of tube; single tooth a long spine with very wide base and several 

 shorter basal spines. Lateral comb of eighth segment of six scales ; single scale 

 elliptical, with stout, curved outer rim bearing a central stout spine and a stout 

 curved subapical one, with smaller spines between and below. Anal segment not 

 longer than wide, ringed by the narrow plate ; dorsal tuft a long hair and brush 

 on each side; a small lateral tuft; ventral brush well developed, extending along 

 ventral line to near base. Anal gills long, longer than the segment, regularly 

 tapered to a sharp tip; each with a slight central trachea. 



The larvae live in ground-pools. Mr. Busck got them in a large pool under an 

 outhouse, twice in pig ponds, once in a slow spring frequented by pigs, and three 

 times in holes in coral rock. 



Island of Santo Domingo, West Indies. 



San Francisco Mountains, September, 1905 (A. Busck) ; Santo Domingo (F. 

 E. Campbell) ; Sanchez (W. J. Zalesky) . 



We recognize Psorophora infine only from Santo Domingo. The specimens 

 cited from Trinidad in the original description belong to Psorophora dngulatus. 



