70 ENTOMOLOGICAL NEWS. [Feb., '13 



Antennae arise from near middle of sides of head; the mouth 

 brushes forming a club at sides of mouth; a very large 

 species Psorophora ciliata 



6. The scales of the eighth abdominal segment are separate 8 



The scales of the eighth abdominal segment, 5 to 8 in number, 



are arranged on a band 7 



The scales are replaced by a series of chitinous bars, arranged in 

 a single row 22 



7. The anal siphon is very large and stout, dilated centrally; antenna 



much longer than head, slender vv^ith an even outcurve or 

 convexity Aedes sayi 



The anal siphon, shorter, stout, dilated nearer the base ; antenna 

 nearly straight, slender, shorter than \\Q.ai6.. .Aedes jamaicensis 



The anal siphon is short, stubby, not dilated ; antenna much longer 

 than the head, very thick medially, bisinuate or with an out- 

 ward and an incurve or convexity Aedes discolor 



8. The scales are not more than 16 in number and form a small 



patch 9 



The scales number 20 or more and form a large patch 12 



9. Anal siphon of moderate length, three times as long as wide or 



longer 10 



Anal siphon short, less than three times as long as wide 11 



ID. About 12 elongate scales in a single row; 12-16 siphonal spines, 

 each with one moderate-sized tooth, and sometimes a few 

 very small ones below it Aedes fuscus 



Scales 10-15, in a partly double row. tapering apically ; siphonal 

 spines 14-18, simple or with 2 or 3 teeth Aedes syhestris 



Scales 7-12 in patch ; a small translucent species, feeding at bot- 

 tom; tracheal gills very long and slender.. Aedes dupreei 



Scales 6-7 arranged in a curve; tracheal gills long, slender, uni- 

 formly tapering Aedes abserratus 



11. A stout black species, the thorax white-banded; antennal tuft 



composed of many hairs; tracheal gills very long, 



Aedes serratus 

 An elongate slender gray species; antennal tuft a single bristle: 



tracheal gills short Aedes iriseriatus 



A large, robust, light species ; anal siphon bottle-shaped, outer 



half linear; anal gills slightly longer than width of ninth 



segment Coquillettidia perturbans 



12. Anal siphon short, not much more than twice as long as broad. 13 

 Anal siphon moderate, from 2% to 3% times as long as broad. .15 

 Anal siphon long, not less than 4 times as long as broad 21 



13. Stout compact larva; antennal tuft of several hairs 14 



