4 DIPTERA 



Anophclines) very hairy. The tf genitalia consist of claspers attached to basal segments which vary in 

 each species. 



The wings have the veins clothed with scales and the posterior border fringed with the same. The 

 scales vary in different genera. In most genera there are median vein-scales and lateral vein-scales; the 

 scales may be uniformly colored [Culcx pipicns, etc.) or may be mottled (Grabhamia, etc.); in some (Theo- 

 baldia) the} 7 are more dense in certain areas giving the wing a spotted appearance. Most Anophelines 

 have spotted wings due to different colored scales and also a few Culicines (Lutsia and Culcx mimeticus) . 

 There are six longitudinal veins in all save the genus Heptaphlebomyia in which a distinct seventh vein 

 occurs ornamented with scales. The fork-cells (first submarginal and second posterior) are usually long 

 (Culex, Anopheles, etc.) but the first submarginal may be very small [Megarhiuits, Uranotania, etc.). The 

 relative lengths of the cells cannot be taken as of any specific importance as they vary in each species 

 and even in the specimens from one batch of eggs. The cross-veins most prominent are the supernumerary 

 mid and posterior, they also vary to a considerable extent in the same species, specially in certain 

 species (Theobaldia incidens, Culex fatigans, etc.). 



Seasonal variation. — The spotting of the wings in the Anophelines has been taken to be 

 of specific importance. The spots are however variable at all times of the year in certain species. The 

 greatest variation occurs however at certain definite seasons, so that we get well marked seasonal 

 variations and dark and light varieties. It is probable that some recently instituted species will thus have 

 to be sunk as seasonal varieties. 



The legs are usually simple, but in some genera may be provided with outstanding scales giving 

 them a ragged appearance (Psorophora, Mucidus) a brush-like appearance (Janthinosoma), or they may 

 be provided with paddle-like groups of hairs [Sabrthes, Eretmapodites). The ungues in the 9 s are equal in 

 size, they may be simple or uni-serrated, in the rjf's those of the fore and mid-legs are unequal and ma} 7 

 or may not be simple or serrated, when the latter, uni-serrated or bi-serrated and a few cases tri-serrated 

 (Anophelines). 



Larval and pupal characters. — The species which present such close affinities that the} 7 

 cannot be separated with any degree of certainty may often be clearl} 7 defined b} 7 an examination of the 

 larvae or pupa?. 



In the Anophelines the frontal hairs of the larvae form the most useful character for differentiation; 

 in the Culicines the grouping of the spines on the spine area at the base of the siphon. In regards 

 to the pupae the form of the siphons is the most important character, but does not vary much in species 

 although generically it is of great use (i). 



The eggs of Culicidae also present great variation. Some are laid singly [Stegomyia] , others singl) 7 

 but afterwards floating together in some definite form {Anophelines) ; in Culex, etc. they are laid in masses 

 or rafts. They also vary in form some being spindle shaped (Stegomyia, Grabhamia), others bottle shaped 

 Taeniorhynchus), some with long thin necks (Mansonia). 



Notes on the classification. — The characters of the three primary genera (Anopheles, Culex 

 and Acdes) are now taken as subfamily characters. To these subfamilies Anophelince, Culicince and 

 Aedeomyiuis are also added the following Megarhinince, Toxorhy minting, Jobloiince, H eptaphlebomyiiue and 

 Corethrina. 



There is some doubt as to whether the last named should be included in the family Culidinae for 

 they have not that characteristic piercing proboscis, nor su:h definite scales; on the other hand the 

 venation of the wings is similar to Culex and thsir life-history also agrees with that of the true Culicidae. 



(i) Recently Dr. Grabham informs me that the frontal hairs of the larvae vary in form in different stages of the same species.. 



