212 MOSQUITOES OF NORTH AMERICA 



middle of inner margin bearing two short, very stent, blunt teeth and a stout 

 spine. Clasp segment small, stout and chitinized like the side-pieces, constricted 

 near base, swollen apically, and bearing one stout and one smaller terminal claw 

 in an apical notch, outer aspect densely clothed with fine hairs. Harpes broad, 

 rounded, terminal margin furnished with a row of about twenty stout, fine even 

 teeth, the stem narrowed. Harpagones divided, with three portions, middle 

 sheath-like, with a row of fine teeth within; inner with the tips pointed and 

 curved inward, not so long as the harpes ; outer portion very long, broad at base, 

 tip rounded, reaching nearly to lateral teeth of side-piece, smooth. Unci form- 

 ing a broad, truncate basal cone. 



Larva, Stage IV (plate 95, fig. 308) . — ^Head rounded, somewhat angular in 

 outline, with a lobe projecting laterally from beneath to cover basal prolongation 

 of mandible ; antennae rather long and slender, uniform, a tuft at middle ; upper 

 head-hairs in fours, lower long and single, ante-antennal tuft multiple. Lateral 

 comb of eighth segment of many spines in a large triangular patch. Air-tube 

 five times as long as wide, slightly tapering on outer half ; pecten of five coarse 

 teeth on basal third of tube; a three-haired tuft at middle; a small tuft near 

 apex and a single hair on dorsal aspect. Anal segment longer than wide, with an 

 iUy defined dorsal plate ; an oblique lateral patch of scale-shaped spines, becom- 

 ing sharper on posterior margin ; a small ventral plate between the brush and the 

 base; lateral tuft small, four-haired; ventral brush large, on a raised barred area, 

 with a small lateral bordering plate; anal gills in form of two low rounded 

 prominences. 



The larvae live in crab-holes in mangrove swamps situated back along the 

 inlets. The water is brackish, sometimes near the surface of the holes, some- 

 times deeper down. Mr. Knab encountered the species far up the mangrove 

 inlets behind Puntarenas. It was established in the holes of a very large and 

 brightly colored species of crab {Cardisoma crassum Smith). These crab-holes 

 were near the head of tide-water, above overflow, often a considerable distance 

 from the water, and the water in them must have been very nearly if not quite 

 fresh. In some of these holes on very low ground the water was qxiite near the 

 surface, and the larvae, in great numbers and of various sizes, could be seen sus- 

 pended by the surface fihn. About Puntarenas, Deinocerites appeared to be the 

 only species of mosquito inhabiting the crab-holes. 



The images likewise inhabit the crab-holes and during the day rest upon the 

 sides of the hole. It takes considerable disturbance to drive them out, and they 

 then fly slowly out of the hole and sometimes to some nearby hole. Usually, 

 however, they alight in the inmiediate vicinity of their hole, upon the ground 

 or very near it, and after a very short interval fly back into the hole. At twilight 

 the adults may be seen dancing in a small cloud close to the mouth of the crab- 

 hole. In moist wheather the adults have been seen swarming in the latter part 

 of the afternoon over the mouths of the crab-holes. Mr. Jennings found the 

 larvae at Corozal in a crab-hole on a hillside in a swamp, in a crab-hole on the 

 flat in front of camp at Miraflores, and at Ancon in similar locations, generally 

 near the shore, but sometimes back from it. 



Atlantic and Pacific coasts of Mexico and Central America. 



Ancon, Canal Zone, Panama, July 13, November 24, 1908 (A. H. Jennings) ; 

 Miraflores, Canal Zone, Panama, June 15, 1908 (A. H. Jennings) ; Corozal, 

 Canal Zone, Panama, December 12, 1907 (A. H. Jennings) ; Eio Ararguez, 

 near Puntarenas, Costa Eica, September 13, 1905 (F. Knab) ; Zihuatanejo, 

 State of Guerrero, Mexico (A. Dug^s) ; Vera Cruz, Mexico, on steamer (L. 0. 

 Howard) ; Nautla, State of Vera Cruz, Mexico, May, 1903 (A. Dug^s) ; Las 

 Penas, Mexico, May 10, 1903 (A. Dugfes) ; Tampico, Mexico (J. Qoldberger). 



