188 NEW YORK STATE MUSEUM 



the Yving margin at or a little below the apex; the cubitus m 

 forked ; the R-M crossvein is at about the mid length of the wing '^ 

 the humeral crossvein is sometimes wanting. 



To the above description I may add that R^-fa is present though 

 usually quite delicate. The male genitalia consist of a dorsal 

 downward curved keel, a pair of elongate lateral lobes, a pair of 

 inferior and a pair of superior lobes (pl.32, fig. 7 to 13) . 



KEY TO SPECIES OF CHIRONOMUS 



Larvae 



The tooth on the middle line of a labium having an odd number of teetb 

 will be called the middle or median tooth, the first tooth laterad of this 

 will be called the first lateral ; the second, the second lateral, and so on. 

 When there is an even number of teeth, the first one laterad of the median- 

 line will be called the first lateral ; the second, the second lateral, etc. 



a Labium with an odd number of teeth (i. e. center line bisects the middle- 

 tooth) 

 J) Middle tooth broadly truncate, pl.21, fig.18 ; pl.23, fig.l5 



c First lateral tooth smaller than the second, second truncate, pl.23y 



fig.15 59. ? p 1 u m o s u s^ 



CG First lateral about same size as the third 16, flavicingula 



dl) Middle tooth rounded 

 c Middle tooth trilobed 



d Teeth short, pl.23, fig.8. . . .' 60. d e c o r u s n. sp.. 



f7(? Teeth long, pl.23, fig.13 ." 79. Chir. sp. 



CO Middle tooth simple 



cl First and second lateral teeth rather closely united, pl.21, fig.l 



G Teeth as shown on pl.21, fig.l 25. tenellus- 



ee First and second laterals more distinctly separated than shown 



on this plate .48, dux n, sp. 



del First and second laterals as distinctly separated as the other 

 teeth 

 e Middle tooth shorter than the first laterals ; blood red larva 



80, Chir. sp. 

 ee Middle tooth as long or longer than the laterals 



f Second and third laterals longer than the first laterals and 



closely united, pi. 37, fig.-27 63a. t e n t a n s 



ff Not as above 



g Second laterals longer than the first and third 



7i As shown on pl.23, fig.l 60a. d o r s a 1 i »^ 



hh As shown on pi. 37, fig.25 63. prasinus 



gg Teeth gradually becoming smaller from the median line^ 

 towards the lateral margin 

 h Teeth almost uniform in size, pi. 22, fig.7. .81. Chir. sp. 

 7ih Middle tooth distinctly larger 



i Middle tooth semicircular, pl.23, fig.3. .52, lobiferus- 

 ii Middle tooth hyperbolic, pl.22, fig.ll. .43, modestus- 



