[Illustration: FIG. 76--A non-malarial mosquito (_T. incidens_), male, standing on the wall.] [Illustration: FIG. 77--Female of same.] [Illustration: FIG. 78--A malarial mosquito (_A. maculipennis_), male, standing on the wall.] [Illustration: FIG. 79--Female of same.] CLASSIFICATION For our purpose it will not be necessary to try to give a system of classification of all the mosquitoes. Those interested in this phase of the subject will find several books and papers devoted wholly to it. It is quite important, however, that we know something about a few of the more familiar groups and kinds, especially those concerned in the transmission of diseases. THE ANOPHELES In pointing out the differences between male and female mosquitoes we noted that in one group, the genus _Anopheles_, both sexes have long maxillary palpi (Figs. 72, 73). This is the most important character separating this genus from the other common forms and as the _Anopheles_ are the malaria carriers it is important that this difference be remembered. Most of the members of this group have spotted wings (Fig. 74), but as some other common kinds also have spotted wings (Fig. 75) this character will not always be reliable. When an _Anopheles_ mosquito is at rest the head and proboscis are held in one line with the body and the body rests at a considerable angle to the surface on which it is standing. Other kinds rest with the body almost or quite parallel to the surface on which they are standing. So if you find a female mosquito with long mouth-palpi and spotted wings resting at an angle to the surface on which it stands you may be reasonably sure that it is an _Anopheles_ and therefore may be dangerous (Figs. 76, 77, 78, 79). In the United States there are three species of _Anopheles_--_maculipennis_, _punctipennis_ and _crucians_--which are common in various localities, and one or two other species that so far as known are local or rare. The _Anopheles_ eggs are not laid in masses as are the eggs of many other mosquitoes, but are deposited singly on the surface of the water where they may be found often floating close together. [Illustration: FIG. 80--Egg of Anopheles, side view. (After Nuttall and Shipley.)] [Illustration: FIG. 81--Egg of Anopheles, dorsal view. (After Nuttall and Shipley.)] [Illustration: FIG. 82--Anopheles larvæ, the one to the right feeding.] [Illustration: FIG. 83--Anopheles larvæ, the one to the right feeding, the other just coming to the surface.] [Illustration: FIG. 84--Anopheles larva, dorsal view.] [Illustration: FIG. 85--Anopheles pupæ resting at surface of water.] The eggs (Figs. 80, 81) are elliptical in outline and are provided with a characteristic membranous expansion near the middle.