1939] 
Mosquitoes of Massachusetts 
125 
2. Both pairs of head hairs consisting of tufts having ap- 
proximately six hairs, all of about equal length : 
impatiens 
Lower head hairs of three or four long hairs, upper head 
hairs multiple and shorter than the lower hairs : 
3. Comb scales in a single row; air tube with a row of 10- 
12 median unpaired tufts along the ventral side be- 
yond the pecten : melanura 
Comb scales in a triangle; air tube without unpaired 
median ventral tufts beyond the pecten : morsitans 
Key to the Genus Psorophoka 
Adults 
1. Mesonotum brown with a median longitudinal stripe of 
brilliant golden curved scales bordered by narrow bare 
stripes ciliata 
Mesonotum uniformly colored _ 2 
2. Claws of the female toothed (Fig. 6) ; wing scales dark : 
■ - - — - posticata 
Claws of the female not toothed (Fig. 7) ; wings uni- 
formly marked with black and white scales : columbine 
Larvae 
1. Both pairs of head hairs single, upper pair very short: 
_ — ciliata 
Both pairs of head hairs not single 2 
2. Upper and lower pairs of head hairs multiple; pecten 
of three to five teeth widely separated on the basal 
half of the tube (Fig. 14) : columbine 
Upper and lower pairs of head hairs double ; pecten of 
three to four teeth on the basal fifth of tube ; tuft of 
air tube absent : posticata 
Ivey to the Genus Anopheles 
Adults 
1. Palpus with white markings 2 
Palpus without white markings 3 
2. Apical segment of palpus entirely white scaled; anal 
vein with three dark spots separated by white (two 
spots in the male) : crucians 
