262 NEW YORK STATE MUSEUM 



tennae of the male and the iisiiallY long, slender proboscis of the 

 female. The thorax lacks the transverse Y-shaped sntnre seen 

 in the crane flies, and the most distinct feature, as stated above, 

 is the scalelike hairs on the wings, specially the margins. The 

 larvae of all species, so far as known, are aquatic in spite of the 

 fact that adults have been observed in arid regions far from water. 

 The characters of greatest service in studying mosquitos, are 

 so plainly shown in figure 5, that no detailed explanation is 

 necessary. It may be well to call attention a little more in 

 detail to the wing structure of this group, which is very inter- 

 esting not so much on account of variations in the veins as in 

 the structure and distribution of the scales. The more impor- 

 tant wing veins may be easily recognized by running back from 

 the costa as follows: subcosta, first longitudinal, second longi- 

 tudinal, third longitudinal, fourth longitudinal, fifth longitudinal 

 and sixth longitudinal, the second and fourth longitudinal veins 

 having the characteristic fork cells, that of the former frequently 

 being termed the first submarginal cell. These two veins are 

 connected by an important cross vein known as the anterior 

 cross vein. It may be easily recognized because it is intercepted 

 near the middle by the third longitudinal vein. The posterior 

 cross vein connects the fourth longitudinal and the anterior branch 

 of the fifth longitudinal veins. The relative distance between 

 these two cross veins and the relative length of the petioles and 

 their fork cells is of considerable service in classification. The 

 male wing may be recognized by the much longer petioles, sparse 

 scales and the absence of oblique scales along the greater por- 

 tion of the posterior margin. The scales of Culicids vary exceed- 

 ingly, ranging from almost linear in Corethra and Sayomyia to 

 the lanceolate ones of Anopheles or the very much dilated scales 

 of Uranotaenia. The latter is remarkable for the diverse struct- 

 ure of its wing scales. The genus Culex presents very interest- 

 ing variations in wing scales. Generally speaking there are two 

 classes — the long and the short, the longer ones being slender, 

 frequently strap-shaped and as a rule extending some distance 

 on each side of the veins, while the short scales are more or less 



