AQUATIC INSECTS IX NEW YORK STATE 415 



are slight constant differences in the form of the air trumpet 

 and in the number and arrangement of the abdominal hairs. 

 Fresh specimens should however be examined in order to char- 

 acterize them correctly. 



The arrangement of the bristles on the abdomen is about the 

 same in all the species examined. On the dorsal surface of the 

 first abdominal segment are a pair of conspicuous stellate hairs, 

 the remaining segments each have about three pairs of lateral 

 discal hairs, and two pairs of small, branched, marginal ones; 

 one of the marginal pairs of the eighth segment being many 

 branched. Besides these there are usually a few scattered 

 hairs. 



Much has been written about the species of this genus, but 

 the fact that most of the older descriptions are inadequate 

 renders the synonymy much involved. Coquillett has done the 

 best and most recent work on the North American species; and 

 the reader is referred to his papers published by the United 

 States Department of Agriculture, or, better still, to his table 

 given in Howard's book on mosquitos, for the determination of 

 the adults. In the last mentioned work will be found a most 

 complete description of the life history of scA'eral species of 

 mosquitos. The recent work of Theobald is a monograph of the 

 Culicidae of the world. 



Dr Dyar has recently published in the Proceedings of the 

 Washington Entomological Society (1902 and 1903) and in the 

 Journal of the New York Entomological Society (1902 and 1903) 

 the descriptions of the larvae of a number of species of Culex, 

 together with keys for their identification. The following key 

 is adapted from one given by him, modified to include species 

 more recently described. 



KEY TO SPECIES OF CULEX LARVAE 



t 



1 Without a longitudinal row of spines on tlie air tube; liair 

 tufts of anal segment confinecl to the barred area; seventh 



segment with a round dorsal plate incised anteriorly 



s i g n i f e r Coq. 



With a longitudinal row of spines or hair on the air tube (2) 



H Air tube at least four times as long as its breadth at the 



base ^3) 



Air tube less than three times as long as broad (9) 



3 -Vntennae with hair tuft beyond tlie middle of the joint (4)- 



The antennal tuft at or before the middle (8) 



4 Air tube six or more times as long as broad; antennae white 



banded (5) 



