94 NEW YORK STATE MUSEUM 



dd Thorax witLout a longitudinal fissure 



e Olaws cleft ; antennae seven-jointed in male and female ; hal- 



teres long (Alaska and Oregon ) 29. Telmatogeton 



ee Claws not cleft 



f Antennae with thirteen to fifteen joints 

 g Antennae with fifteen joints; wings spotted (West Indies 



and Mexico) 5. O e c a c t a 



gg Antennae with fourteen or fewer joints 



h Thorax rounded, not produced over the head ; antennae 



with thirteen or fourteen joints ; legs of moderate 



length 



I Antennae with thirteen joints ; wing as figured, pl.35, 



fig.lO. Palpi with three joints. (=L eptoconops 



Skuse?) 2. Tersesthes 



a Antennae with fourteen joints ; wing venation as figured, 

 pl.l7, figs. 13 to IG. (Go hack to the Group C er at- 

 op o g on hh on p.92 of the previous key.) 

 // cC- hh Thorax produced over the head, legs usually long ; 

 antennae of male with the fourteenth joint long, slen- 

 der, and plumose (female with seven joints). (Go 

 hack to group C h i r o n o m u s mm, p.91 of previous 

 key. ) 



Tlie subdivision of tlie Group Ceratopogon into smaller 

 genera and subgenera as given in the first key is adapted from 

 one given by the Abbe J. J. Kietfer (1902), with some slight 

 modifications. The three South American genera Psycho- 

 phaena, Tetraphora, and Didymorphleps. have 

 been omitted from the key. They are probably synonymous with 

 previously described genera, though from the brief descriptions 

 il. is impossible to say. They all belong to the Group Ceratop- 

 ogon, and their descriptions are all reproduced upon a subse- 

 quent page. 



Genus 1. Leptoconops Skuse 



Proc. Linn. Soc. N. S. W. 288. 1889. (Pl.35, fig.l4) 



Antennae in female 2h-11 jointed; firet joint of scapus large, 

 discifonn; second smaller, globose; IhigQllar joints globose, 

 gradually diminishing in size, more ovate towards apex, terminal 

 joint elongate-ovate. Proboscis prominent. Palpi four-jointed ; 

 first and second joints small, third greatly incrassated, about 

 three times the length of the first or second; fourth not as long 

 as last, slender cylindrical; wings naked. All longitudinal veins 

 taking their origin at the base of the wing. Venation as figured. 

 Australian species. 



