REPORT ON MOSQUITOES. 197 



Description of the Larva. 



The larva which is shown on figure 58 is yellowish hrown in 

 color when full grown. It measures from 7 to 8 mm. ,=.28 to 

 .32 of an inch in length including the anal siphon.- and is rather 

 short and stout. The head is almost as large as the thorax, one 

 and one-half times as broad as long, excavated immediately be- 

 fore the antenna and square in front; it is pale yellow, without 

 markings of any kind, and from the center of the vertex arise 

 four hairs,' each from a separate pit, and a tuft of four or five 

 hairs at the base of each antenna. The antenna is large and 

 white, partly covered with small stout spines, almost as long as 

 the head is broad, thickest centrally, and with an out and an in- 

 curve, terminating almost to a point. The tuft is well below the 

 middle and consists of about a dozen hairs. The two long' 

 spines, midway between the tuft and the apex, represent two of 

 the four spines which usually crown the apex ; the apex with two 

 short articulated spines and a small joint. The eyes occupy the 

 sides of the head and are crescent-shaped, with a small detached 

 portion at its posterior margin. The hairs composing the rotary 

 mouth brushes (fig. 2) are simple. The mentum (fig-. 3) is 

 triangular, broader than long and is very constant in form, with 

 eight teeth on each side of the apex. 



The mandible (fig. 6) is of the usual form, but is peculiar by 

 possessing only a single dorsal spine. The maxillary palpus 

 (fig. 5) is scantily clothed with hair, while the apical tuft is 

 rather large and of long hair. The basal joint is small with a 

 number of very small spines at its apex. 



The thorax is wider than long, wath rounded margins and mod- 

 erately long hair tufts. When the larva is about to change into 

 the pupal condition, the thorax becomes shriveled, the dorsal sur- 

 face depressed and large prominences form on the anterior mar- 

 gin, giving the impression of an entirely difli'erent species. 



The abdominal segments i to 3 have lateral tufts of hair, each 

 with four to six hairs, while seg-ments 4 to 7 have only two hairs 

 to each tuft. The eighth segment is prolonged upward on the 

 dorsal part to receive the odd shaped base of the siphon. The 

 lateral combs consist of from five to eight scales, arranged in 

 the form of an arc on a separate band, fringe-like, as shown in 

 figure 8. The individual scale is oblong, with three stout spines 

 directed downward, the central one very much long^er than the 

 other two, and the sides also fringed with spines (fig. 9). The 

 anal siphon is very small, three times as long as broad in its 

 greatest length and with two small, curved spines at the apex; 



