of each maxilla, as seen upon the basal portion of fig. 5, w.r. In some species 

 of Cuh'.i' this feathering is right-angled with the direction of the chitiii rod; in 

 other species oblique-angled, with the angle pointing forward, so as to 

 form a series of barblike corrugations. The tip of the maxillae (fig. 5, /,') 

 is very acute, has none of the before-mentioned chitinous corrugations, but, in 

 their place, near the outer edge, is a row of papillae, which have their tips 

 slightly recurved toward the head, and consequently appear serrate. These papillae 

 are different in number in different species, and probably in different individuals 

 of the same species. That they are true papillae, and not points of a serrate 

 edge, is not always at first apparent, but becomes so by observing them in all 

 directions, and is still further shown, in certain species of Culex, where they are 

 situated near the middle of the blade of the maxilla. These papillae are upon 

 the upper surface of the maxillae, as can be readily seen, by preparing the mouth- 

 , parts by lateral pressure, as in fig. 1. 



The maxillary palpi (figs. 1 , 2, and 9, mp.~) are four-jointed in some species 

 of Cule.r, five-jointed in others. At first sight they appear to be three-jointed, 

 but more careful examination serves to show that the apparent basal joint is 

 made up of two joints, and oftentimes to reveal a very short, knob-like joint at 

 the extremity of what appears to be, at first, the apical joint. At their base the 

 maxillary palpi join the maxillae just before the latter pass beneath the clypeus, 

 and, with the maxillae, join the other mouth-parts, as shown, in section, by fig. 9. 



The function of the maxillae is, probably, to draw the other mouth-parts into 

 the skin, when (. 'nh>,i- bites, for if one watches the maxillary palpi of Cuk.v, while 

 the 'setae are entering the skin, the setae seem to pierce the skin, and enter it 

 with a slow gliding motion, as if drawn from below, instead of pressed from 

 above ; meanwhile, if one observes carefully, with a lens, the maxillary palpi can 

 be seen to be in an alternating motion, as if the maxillae to which they are 

 attached, pressed, first one then the other, into the skin, and then pulled the 

 other parts after them. The muscles, retractores maxillarurn, already described, 

 lend weight to this view of the functions of the barbed maxillae. 



The labium .(figs. 1, 2, and 3, /), the largest of the mouth-parts of Culex, 

 and the only one of them, helping form the proboscis, which contains muscles, 

 forms a sheath opening along the upper side, and receiving in its channel the 

 other mouth-parts (excepting the maxillary palpi), as seen in cross-section in 

 fig. 8; it tapers from base to tip, is flexible, has a delicately aunulated structure., 

 and is clothed with hair and scales. At its base it unites with the maxillae, 

 mandibles, and hypopharynx, and continues into the under surface of the head. 

 Throughout its length it contains, on each side, muscles, which have their origin 



2 



