188 NKW YORK STATIC MT-SRUM 



the wing- margin at or a little below the apex; the cubitus i» 

 forked; the R-^Nf 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^j.. 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.:52, fig. 7 to 13). 



KEY TO SPECIES OF CHIRONOMUS 



Larvae 



Tbe tooth on the iniddle line of a kibiuui 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 mediaa 

 line will be called the fir(^t lateral ; the second, the second lateral, etc. 

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

 tooth ) 

 & Middle tooth broadly truncate, pl.21, fig.18 ; pl.23, fig.15 



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



lig.1.5 59. ? p 1 u m s u s 



cc First lateral about same size as the third 16. flavicingula 



1)1) Middle tooth rounded 

 c Middle tooth trilobed 



d Teeth short, pl.23, fig.S W. d e c o r u s n. sp. 



(Id Teeth long, pl.23, fig.l3 79. C h i r . sp. 



cc Middle tooth simple 



d First and second lateral teeth rather closelj' united, pl.21, fig.l 



c 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. 



(/(/ First and second laterals as distinctly separated as the other 

 tooth 

 r ]\riddle tooth shorter than the first laterals ; blood red larva 



80. O h i r . sp, 

 er Middle tooth as long or longer than the laterals 



f Secon<l and third laterals longer than the first laterals and 



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



ff Not as above 



g Second laterals longer than the first and third 



/( As shown on pl.23, fig.l (X)a. d o r s a 1 i s 



hh As shown on pl.37, fig.25 63. p r a s i n u s 



gg Teeth gradually becoming smaller from the median line 

 towards the lateral margin 

 // Teeth almost uniform in size, pl.22, fig.7. .81. C h i r . sp^ 

 hh Middle tooth distinctly larger 



1 Middle tooth semicircular, pl.23, fig.3. .52. 1 o b i f e r u s 

 a Middle tooth hyperbolic, pl.22, fig.11 . .43. m o d o s t u s 



