LIMATUS CACOPHRADES 47 



of third tarsal joint silvery beneath. Wings hardly narrower than in the female, 

 the stems of the fork-cells somewhat longer. Claw formula 0.0-0. 0-0-. 



Length : Body about 2 mm. ; wing 2.5 mm. 



Grenitalia (plate 2, fig. 2) : Side-pieces short, about twice as long as wide, 

 tips excavate for the insertion of the clasp-filament; clasp-filament long, with 

 uniform stem, the tip divaricate, the inner branch smaller, cleft at tip, and 

 bearing a row of setae ; outer branch with a row of coarse, blunt teeth. Harpa- 

 gones and harpes small, the later toothed at tip. Basal appendages low, rounded, 

 setose. 



Larva, Stage IV (plate 86, fig. 273). Head rounded, about as long as 

 wide, a slight notch at insertion of antennae, front margin evenly arcuate. An- 

 tennas small, cylindrical, smooth ; a single hair at outer fourth, a long hair, two 

 short ones, and a long digit at tip. Eyes small, round. All three pairs of 

 dorsal head-hairs and ante-antennal hairs simple. Mental plate triangular, 

 short, a large apical tooth constricted on the sides and seven on each side 

 which are somewhat more remote basally. Mandible quadrangular, the denti- 

 tion highly produced; a filament from a notch before apex; an outer row 

 of cilia; a row of six long filaments from outer margin; dentition of five teeth 

 on a thick process, the second one longest; a serrate filament within; process 

 below short and blunt, lying in line with front margin, obscurely furcate, with 

 tufts of hair ; a row of long hairs within ; basal angle absent ; a row of long 

 hairs at base. Maxilla hemispherical, short, and broad; tip truncate with a 

 series of short triangular teeth; inner half with two rows of cilia; outer half 

 with a row of long cilia at middle, preceded by a long articulated filament ; a 

 tooth-shaped spine near base, with a band of cilia ; a small spine near palpus. 

 Palpus proportionately rather large, with two moderate and two minute digits. 

 Thorax rounded, moderate; hairs rather abundant, not long. Abdomen long 

 and slender, the anterior segments shorter; lateral tufts multiple on first two 

 segments, triple on third to sixth. Tracheal tubes slender. Air-tube small, 

 basal half thick, outer half very strongly tapered; a row of three double hair- 

 tufts on dorsal, seven on ventral aspect; no pecten. Lateral comb of eighth 

 segment of six or seven well-separated scales in a line ; single scale smooth, thorn- 

 shaped, with elliptical base. Anal segment about as long as wide, with a dorsal 

 plate reaching well down on sides; dorsal tuft of six long hairs on each side; 

 two long lateral hairs ; no ventral brush, but a tuft of three long hairs on each 

 side of the ventral line. Anal gills twice as long as the segment, with rounded 

 tips, both pairs equal in length. 



The larvas live in water of a foul nature, rich in decomposed vegetable matter, 

 collected in cocoanut-husks, palm-leaves, and various receptacles on the ground. 

 The eggs are unknown. The adults are diurnal and will bite man, being fairly 

 aggressive for a sabethine. They frequent forests. 



Central America, Panama, and probably southward. 



Sonsonate, Salvador, larvas in cocoanut-husks in a plantation, August 30, 

 1905, preyed upon by Megarhinus moctezuma (F. Knab) ; Port Limon, Costa 

 Pica, larvas in an old sprinkling-can, found in a swamp near town, associated 

 with Aedes calopus (F. Knab) ; Tabernilla, Canal Zone, Panama, larva in an 

 old tin bucket, in water in leaves of a bromeliaceous plant, in bamboo, and in a 

 small wooden barrel near houses, July 10-18, 1907, associated, in the case of the 

 bromelia larvae with Culex jenningsi and Wyeomyia circumcincta (A. Busck) ; 

 in rain-water in a fallen palm-leaf on the bank of the upper Chagres Eiver, 

 Panama, June 7, 1907, associated with the larva of Anopheles eiseni (A. Busck) ; 

 Bas Obispo, Canal Zone, Panama, larvae from artificial receptacle, July 16, 1908, 

 associated with tadpoles and larvse of Culex (A. H. Jennings) ; Panama terri- 

 tory, near Ancon, Canal Zone, in an old tin can, July 22, 1908 (A. H. Jennings) ; 



