MOSQUITO BIOLOGY 95 



Head is rounded, as long as broad, with distinct offsets for reception of 

 antennae ; pale yellowish brown with basal half of vertex maculate with 

 brown as shown in Fig, XXIX. There is some variation in size ; smaller 

 spots may be consolidated with larger ; but it is always well defined and 

 seemingly very constant in form. Maculation of same pattern present 

 also in young larvae. In middle of vertex, in transverse row, six rather 

 long, equally spaced feathered hairs ; several small, similar ones situ- 

 ated farther back. Eyes crescent-shaped with small spot in concavity. 

 Antennae (Fig. XXIX) two-jointed, first very short, immovably at- 

 tached to head, second comparatively long, thickest near base, tapering 

 evenly toward apex and terminated by six long hairs and two spines, 

 latter serrated on one edge. Surface of second joint set with small 

 spines, and four-branched hair representing tuft, situated on shaft at 

 about one-fourth its length from base. Rotary mouth brushes very 

 small, but dense, and composed entirely of simple hair. Mentum some- 

 what pentagonal, two front angles with five large blunt teeth, sides with 

 two smaller pointed teeth, and basal angles greatly elongated. Mandible 

 (Fig. XXIX) stout and chunky, with two large and several smaller 

 teeth at apex, two spines below serrated on inner edge ; on dorsal sur- 

 face three large curved spines, one simple, others feathered on one side. 

 Few hairs of dorsal terminal part of transverse fan also branched. 

 Maxillary palpus (Fig. XXIX) elongate, with four stout spines and 

 two lamellate processes at apex ; at about one-third from apex issues a 

 stout hair which divides into a number of branch hairs. 



Thorax subquadrate, angles rounded, each angle with three or four 

 long feathered hairs ; two smaller simple hairs on each side between 

 them ; several similar, small hairs on dorsal surface. 



Abdominal segments transversely oblong anteriorly, becoming sub- 

 quadrate posteriorly ; first two have each two long feathered hairs lat- 

 erally, third but one ; four succeeding segments have from two to four 

 rather short simple hairs on each side ; very small simple and feathered 

 hairs at base of long hairs on all segments. On dorsal surface, near 

 bases of segments three to seven, two small palmate hairs, and in center, 

 at apical margin of segments one to eight, small chitinized plates and 

 sometimes extremely small circular dots below them. Eighth segment 

 bears respiratory apparatus; very complex organ, which projects 

 backward over ninth segment as seen in side view. Tracheal tubes open 

 on dorsal surface of this structure by two stigmata, and immediately in 

 front of these is small plate which folds over stigmata when they are 

 not in communication with the outer air. Posterior to these openings 

 large partly chitinized squarish area, which comes in contact with air 



