416 NEW YORK STATE MUSEUM 
Air tube 4 or 5 times as long as broad...... St olds ojos ane Ce (6) : 
5 Tube concave, the tip wider than the terminal portion. 
Spines of tube mostly with a single baSal branch....... territans 
Tube regularly tapered, smallest at the tip. Spines of the 
tpe-3 =to.7 Dramched es. oe os ey oie ee ee eee ee nigritulus 
6 Anal segment without hair tufts anteriorly of the trans- 
versely barred afea..... 2.22.00 64 Fe «es seem wens end «hey on ar (7) 
Anal segment with hair tufts on the ventral line up to the 
| 6: ot <a ge A ie ee nem st Mgt ee dyarft 
7 Lateral comb of the eighth segment a patch of spines; tube 
PLOW: 525 0% 26 SSE Rig ie Renee Cote o's eee ee wis eee Slate a pipiens 
Lateral comb a row of bars; air tube black............ melanurus 
8 Apex of the labium rounded [pl.44, fig.1]. Antennae whit- 
ish on: asal salt eee ts, sia Re lochs cad cs lees cites Se restuans 
Apex of labium pointed [pl45]. 22 ie... sd... 8 ns 2 oe eee ee Ca nia ms 
9 Lateral comb of the eighth segment a patch of small spines 
three: OF MOLe TOW S GECP. vc vic cis odie ew eles ce ena Glaus or enniel oe (10) 
Lateral comb a few spines on a single or partly double row........ (13) 
10 Anal segment with hair tufts before the barred area..............-. (11)- 
Anal segment without tufts before the barred area................ (12). 
11 The spines of the air tube prolonged into setae; tube about 
12 
13 
14 
16 
three times as long as wide; the antennal tuft is at the mid- 
OTOP ELIS, JOU Gs ro oie ccm sonic. cic te he ete. sa mem tal det eee consobrinus 
The air tube with spines, anal segment broadly plated..canadensis 
Antenna with a small tuft a little before middle of the joint. 
Air tube about two and a half times as long as wide; 
lateral comb about three rows deep..........eceee bimaculatus 
Antenna with a single inconspicuous hair instead of a tuft. 
Air tube not over twice as long as wide; lateral comb 
about five: rows GeEpss Sueis.c.. uly meee ne Seb ee eee atropalpus 
Anal segment with hair tufts before barred area............0+se++ (le) 
Anal segment without tufts before barred area.......... Pre (16) 
Comb of eighth segment of separate nearly simple spines, 
the spines of the air tube each with three teeth....... sylvestris 
Comb of eighth segment either toothed or digitate................. (15) 
Comb of eight segment composed of spines with finely digi- 
tately divided tips; antenna with a single long seta instead 
OL Ee LUTE B iiS's Sa. Stabe S's Salty nly 0 ce We eee ease, Sane ee ey triseriatus 
Comb of conspicuously toothed spines, joined on a weak 
basal plate. Antenna with a small hair tuft.......jamaicensis 
Comb of eighth segment of nearly simple, thorn-shaped 
NOCTBL, oe oc ulliligte ws calm iee mics a el a hein ta ee ee aa ee sSollichiaits 
Comb of eighth segment of pectinated spines in an incom- 
plete- double Pow. sai. tions se Aas bake eee taeniorhynehus 
The pupae resemble each other so closely that I have been 
unable as yet to find satisfactory characters to distinguish them. 
ee 
