870 MOSQUITOES OF NORTH AMERICA 



elongate, subcylindrical, enlarged towards apex beyond fifth segment ; fifth to 

 eighth segments with dorsal silvery bands ; last segment with numerous coarse 

 black setfB. Wings narrower than in the female, the stems of the fork-cells 

 longer, that of the second marginal cell being as long as its cell ; vestiture sparse. 

 Claw formula, 1.0-1.0-0.0. 



Length : Body about 4 mm. ; wing 3 mm. 



Genitalia (plate 23, fig. 163) : Side-pieces twice as long as wide, rounded 

 at tip; basal lobe represented by a large area of small set^ with tuberculate 

 bases, a row of large outstanding scales on distal part of inner aspect. Clasp- 

 filament long and slender, with an articulated subapical blunt claw. Harpes 

 slender, subspatulate, inner margin thickened, tips recurved in a sharp hook, 

 spined on inner side. Harpagones with a long columnar base, a few setag along 

 its sides, the tip expanded into a broad, thin, twisted leaf-like plate with a 

 thickened edge. Unci contiguous, revolute, forming a large basal cylinder. 



Larva, Stage IV (plate 126, fig. 439). Head rounded, widest through eyes, 

 a slight notch at insertion of antennae, front evenly rounded. Antennae small, 

 slender, uniform, a small single hair near middle. Upper pair of dorsal head- 

 hairs single, long, lower pair double, smaller, situated far down on the face; 

 ante-antennal tufts small, in threes. Skin of body smooth. Lateral comb of 

 the eighth segment of about twenty rather large scales in a patch three rows 

 deep in middle, each scale broad, bluntly rounded, smooth. Air-tube stout, 

 about two and a half times as long as wide, tapering outwardly, pecten of evenly 

 spaced teeth not reaching to the middle, followed by a single three-haired tuft. 

 Ana] segment longer than wide, with a dorsal plate reaching beyond middle 

 of sides, emarginate laterally; dorsal tuft a long hair and tuft on each side; 

 lateral hair at angle of plate double, long; ventral brush well developed with 

 some tufts preceding barred area, a small lateral chitinous triangular plate on 

 either side of barred area ; anal gills broad, blunt, short, upper pair not as long 

 as the segment, lower pair much smaller. 



Mr. Knab found the larvae in old cocoanut-husks containing foul water ; Mr. 

 Urich found them in open water-filled bamboo-joints at Trinidad; Mr. Busck 

 and Mr. Jennings found the larvag most frequently in holes in trees. Mr. Busck 

 obtained the larvse from a pot-hole in a rock on Taboga Island. Mr. Jennings 

 twice found them in a stream, their presence there probably being due to the 

 emptying of some receptacle which had contained them. The larvae normally 

 inhabit water in hollow trees. 



We have no further observations on the life history. 



Mainland of tropical America. 



Sonsonate, Salvador, August 30, 1905 (F. Knab) ; Cacao, Trece Aguas, 

 Alta Vera Paz, Guatemala, April 26, 1906 (Schwarz & Barber) ; Livingstone, 

 Guatemala, May 11, 1906 (H. S. Barber) ; Gatun, Canal Zone, Panama, June 

 10, 1907 (A. Busck) ; Ahorca Lagarto, Canal Zone, Panama, June 12, 1907 

 (A. Busck) ; Tabernilla, Canal Zone, Panama, June 4, 1907 (A. Busck), 

 December 22, 1908 (A. H. Jennings) ; Las Cascadas, Canal Zone, Panama, 

 July 17, 1907 (A. Busck) ; Taboga Island, Panama Bay, Panama, July 13, 

 1907 (A. Busck) ; Matachin, Canal Zone, Panama, May 5, 1908 (A. H. Jen- 

 nings) ; Ancon, Canal Zone, Panama, July 1, 1908 (A. H. Jennings) ; Trini- 

 dad, British West Indies (F. W. Urich, A. Busck) . Reported also from British 

 Guiana (Theobald). 



HcBmagogus alhomaculatus is closely allied to H. splendens and occupies the 

 same geographical region. It presents, however, certain differences in all the 

 stages, so that we have no doubt that there are two distinct, although closely 

 allied species. 



Hcemagogus alhomaculatus was founded upon the presence of a large seta on 

 the fourth abdominal segment; we had seen no specimen showing such a 



