The Mosquitoes of New Jersey 21 



4. Abdomen with four tracheal gills at tip 5 



Abdomen with two thracheal gills only ; a small whitish species with 

 head rounded and thorax suhquadrate. . . .IVycomyia smithii. (p. 159) 



5. Antennae arise from sdies of anterior part of head 6 



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. (p. 120) 



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; antennae 

 much longer than head, slender with an even outcurve or convexity, 



Psorophora sayi. (p. 120) 

 The anal siphon, shorter, stout, dilated nearer the base ; antennae nearly 

 straight, slender, shorter than head. .Psoropliora coluinbiae. (p. 124) 

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

 than the head, very thick medially, bisinuate or with an outward and 

 an incurve or convexity Psorophora discolor, (p. 126) 



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 li 



10. About 12 elongate scales in a single row ; 12 to 16 siphonal spines, each 

 with one moderate-sized tooth, and sometimes a few very small ones 



below it Acdes fuscus. (p. 151) 



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



14-18, simple or with 2 or 3 teeth Acdcs sylvestris. (p. 130) 



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



tracheal gills very long and slender Aedcs dupreei. (p. 140) 



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

 tapering ". Acdes abserratus. (p. 142) 



11. Stout black species, the thorax white-banded; antennal tuft composed 

 of many hairs; tracheal gills very long. .Acdcs atlanticus. (p. 140) 

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



gills short Acdcs triscriatus. (p. 137) 



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

 linear; anal gills slightly longer than width of ninth segment 



Mansonia perturbans. (p. 107) 



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 



Long slender larva, antennal tuft of i or 2 hairs ; 25 to 35 scales in 

 patch; 17 to 21 siphonal spines with 2 or 3 long teeth at base 



Acdcs atropalpus. (p. 134) 



14. Scales 14-22, with stout apical and slender lateral spines ; 13 to 18 



