36 The Mosquitoes or Culicidae of Jamaica. 



small, equal and simple ; in the male the fore and mid legs have 

 unequal ungues, the larger in both uniserrated, the smaller 

 simple ; hind ones rather long, thin, curved and simple. 



Length. 4 to 5 mm. 



Geographical distribution. St. Vincent, St. Lucia, Barbadoes, 

 Jamaica and British Guiana. 



Life-history and habits. This is a "crab-hole" breeding form, 

 the water in which they occur being brackish. The larvae occur 

 at the bottom of these crab-holes, near the sea. The crab-holes 

 are long winding passages, sometimes three or four feet long and 

 only about four inches in diameter. The live insects hold their 

 long antennae stiffly out in front, somewhat arched downwards 

 and kept in constant movement exploring the surface as the 

 insect crawls. At the end of the second joint are a number of 

 peculiar sense organs (Giles) which are probably olfactory organs. 

 They are sluggish in flight, and, when disturbed, Dr. Low 

 noticed that they fly slowly from one hole to another. The eggs 

 are not known. The larvae are grey with a dark median line, 

 chestnut-brown head and brown siphons, which are thick and 

 as long as the two preceding segments and the one on which 

 they are situated. In the adult larva, Dr. Grabham says, the 

 siphon is nearly cylindrical, many times longer than broad ; the 

 pecten composed of six to seven deeply bind or trifid bristles, a 

 pair of long bifurcated hairs about the middle and a pair of 

 short simple hairs below the free end. 



Lateral comb of the eighth segment composed of numerous 

 simple curved bristles, the posterior the longer. There are trifid 

 plumose hairs below the base of the siphon. The ninth segment 

 has a chitinous dorsal plate as shown in the figure. Anal papillae 

 reduced to two curved lateral lobes. Ventral chitinous plate 

 small, mentum with fifteen to twenty bifurcated teeth. Antennae 

 with a median tuft of four to six hairs, and on the apex two 

 long and two short hairs and two spines. The first thoracic 

 segment has numerous simple hairs in front and two pairs of 

 bunches of plumose hairs arising from conical papillae on each 

 side; the second segment has four lateral hairs, two long and 

 plumose and two short, the third to sixth with a pair of finely 

 plumose hairs on each side, the seventh with a single long hair. 

 The length of the siphon varies according to age. 



Length. 6 mm. 



The pupa has truncated siphons and two anal fins. The 

 length of the various stages is not known. 



