The old genus Anopheles has been divided by Theobald into 12 new genera. The basis of this classification is almost entirely dependent on scale structure.

1. Anopheles

Thorax and abdomen have hair like, curved scales. Palpi not densely scaled; lateral scales of wing veins long and lanceolate. Spots on the wing few, or absent in some species.

2. Myzomyia

Thorax and abdomen with hair like, curved scales. There may be a tuft of narrow curved scales in front of the thorax, projecting forward. Wings spotted and distinguished from those of the genus Anopheles by little beyond the shape of the lateral scales of the wing veins, which are long thin scales, but narrow lanceolate also occur. They are very often small dark mosquitos.

3. Cyclolepidopteron

Thorax and abdomen with narrow, curved, almost hair like scales. Head covered with upright forked scales. Easily distinguished from the two previous genera by the wing scales. Besides the lanceolate scales, there are characteristic large inflated scales.

4. Stethomyia

Thorax bristly, apparently nude, prothoracic lobes mammillated and bearing bristles. Abdomen very hairy- large and small hairs. Wings unspotted; the veins have long lanceolate scales. Easily distinguished from Anopheles by its mammillated prothoracic lobes and by the presence of some flat scales on the head, which are not found in Anopheles.

5. Pyretophorus

Thorax with narrow curved scales; abdomen, hair like scales; wings distinctly spotted. Scales of wing veins, narrow or lanceolate. Palpi; fair amount of scales. Legs generally banded or even spotted. Distinguished from Myzomyia by its thoracic scales. Has no flat scales on the head.

6. Arribalzagia

Thorax with hair like scales and some narrow curved; abdomen has large apical lateral scale tufts. Palpi densely scaled. Legs banded and speckled. Closely related to the next genus.

7. Myzorhynchus

Thorax, hair like scales. Abdomen no lateral scale tufts, but a ventral apical tuft. Palpi densely scaled, distinguished from the former by the absence of the lateral scale tufts.

8. Christya

Thorax with hair like scales and narrow curved lateral ones; abdomen with dense long lateral apical tufts of hairlike scales (characteristic). Wings dense lanceolate scales.

9. Nyssorhynchus

Thorax has narrow curved and spindle shaped scales, abdominal scales variable in character and quantity; sometimes ventral, sometimes on the apical segment only, sometimes with dorsal apical patches. Palpi densely scaled. Wing scales lanceolate.

10. Cellia

Thorax, flat spindle scales. Abdominal scales differ from those of Nyssorhynchus by the fact that they almost completely cover the abdomen. The scales are narrow curved or spindle, with dense lateral tufts. Palpi densely scaled. Wings densely scaled, with blunt lanceolate scales, differing from those of Nyssorhynchus.

11. Aldrichia

Thorax, hair like scales. Prothoracic lobes have projecting flat scales. Characterized by the abdomen being covered with flat scales, as in Culex.

12. Genus Lophoscelomyia

Resembles Nyssorhynchus, but differs from it in having-(1) Long, curved, hair like scales on the thorax instead of narrow, curved, and spindle shaped ones; (2) marked dense apical tufts on the hind femora in both sexes.

Differentiation Of Species

Some of the Anophelince can be readily told by merely examining the wing or the banding on a leg, though it should be remembered that a too hasty examination is apt to lead one to overlook new species and even genera. The main features that are of use are-(1) The wings: (a) The main spots of the wing are formed by collections of scales on the costal, subcostal, and first longitudinal veins; these sometimes exhibit characteristic arrangements-e. g., the T spot in M. rossii or the interrupted spot of P. costalis. It should be recognized that variations occur in these spots, and that they are by no means constant, so that small differences do not suffice to create a new variety, much less a species. This may be seen in a number of Anophelince bred out from the same batch of eggs, but the number and arrangement of the spots are, all the same, of great use in distinguishing species. (6) Besides the main costal spots, the small areas of scales on the third to the sixth long veins are of use, and in an accurate description of a wing each of these areas should'be marked. Thus M. leucosphyrus has six spots on the sixth long vein, while M. elegans has only four, (c) The extent to which the third longitudinal vein is scaled is also of specific importance, (d) Finally the wing fringe has at the points where the longitudinal veins cut the margin a variable number of pale areas. Thus A. punctipennis has only one pale area, while A. pseudopunctipennis has several; M. rhodesiensis has one small apical fringe spot; M. funestus, six spots. (2) The legs: The tarsal segments may be banded or speckled. The banding may be apical or basal on the tarsal segments. Many of the species of the genus Nyssorhynchus can be distinguished at once by the number of white tarsal bands, which may vary from one to three and a fraction of the next segment. The femora and tibiae may be speckled or unspeckled. Similarly in the genus Cellia. Most of the species are easily told by simply examining the tarsi of the hind legs. (3) The palpi: Just as in the case of the legs, so by the banding of the palpi formed by collections of white scales great assistance is given in the determination of species. The apices of the palpi are, as a rule, white, but they are dark in M. rhodesiensis, M. hispaniola, M. turkhudi, and in N. iheobaldi var. nagpurensis. Besides the apical band, the other bands are of great aid-e. g., the number of bands, their distance apart, whether or not the two apical ones are equal in width, and so forth. It should always be remembered, in making minute comparisons, that an observed difference may be found normally in the species, and the occurrence of seasonal variations has also to be considered. Of minor importance are the characters of the male genitalia, the character of the ungues in the male and the position of the cross veins on the wings; this latter is, indeed, of but slight use.