REPORT ON MOSQUITOES. 247 



gray or yellowish brown in color with the thorax somewhat 

 darker. The head is about one and one-half times as broad as 

 long, yellowish to light brown, though the vertex is often darkly 

 clouded SO- as to give the appearance of a dark brow^n head. The 

 posterior part of the vertex has a maculation of four spots and 

 a semi-circular blotch, which are often obscured by the clouds. 

 Four tufts of two hairs each are situated on the top of the head 

 in the anterior part and a larger tuft is at the base of. each antenna. 

 The antenna (fig. 74, 4) is moderately long, somewhat sharply 

 curved, the surface sparingly set with spines, rather thickly at 

 the base, and three or four regular rows of minute spines run 

 from the base toward the apex on the inner side. The tuft is well 

 below the middle and consists of but two or three hairs. In color 

 the antenna is brown, very dark toward the tip, the apex with 

 three spines of different lengths, a very short spine and a small 

 joint. The eyes are large and black and the rotary mouth brushes 

 (fig. 74, 2) are pectinated in the central hairs. The mentum 

 (fig. 74, 5) has slightly curved edges of eleven or twelve teeth 

 on each side of the apical one, and becomes very broad at the 

 base. The mandible (fig. 74, 5) is normal, with a group of small 

 spines at the base. The maxillary palpus (fig. 74, 6) is set with 

 spines and patches of hair over the surface and has a chunky 

 little joint at its base. 



The thorax is as long as broad, only slightly angulated at the 

 sides, the lateral tufts moderately long and, in addition, there are 

 two very small tufts on the anterior margin. 



The abdominal segments from one to seven are oblong or sub- 

 quadrate in form, with three or more hairs to the lateral tuft in 

 the first and second segments, and two hairs to the tuft in the fol- 

 lowing segments. The eighth segment has from twenty-four to 

 thirty scales to each of the lateral patches ; the single scales long, 

 with three spines at the apex and very fine ones along the sides. 

 The anal siphon (fig. 74, 7) is pale yellow in color, slightly darker 

 near the tip, very long, being about five times as long as its width 

 at the base and evenly tapered toward the apex. The spines, 

 from fifteen to twenty-two in each row, extend almost to the 

 middle ; they vary in size, and in the number and length of the 

 teeth as shown in figure 74, 8 ; the short ones always toward the 

 base; the apical two longest and separated from the rest and 

 from each other. The siphonal tufts at the end of the row have 

 but three or four long hairs. The ninth segment is slightly longer 

 than broad with the usual dorsal and ventral tufts. The anal gills 

 are stout and moderate in length without visible trachea. 



The larva dififers obviously from that of cantons in the anten- 

 nal structure, in the form and arrangement of the scales on the 

 eighth segment and in the form and armature of the anal siphon. 



