354 NEW YORK STATE MUSEUM 



Mandible with a pair of apical bristles, palpus of the maxilla 

 with setae (8) 



8 Middle tooth of the labium enlarged, ventral surface of 



labium with five pairs of setae [pi. 37, fig.6] venustum 



Middle tooth not enlarged (varieties of venustum) (9) 



9 Labium with four pairs of ventral setae [pl.37, fig.l4] var. a 



With seven pairs of setae [fig-S] var. p i s c i c i d i u m 



Pupae 



(Arranged according to the number of filaments in each respiratory 

 tuft) 



1 With six filaments 



a Legs in their cases appear blcolored' venustum 



/) Legs unicolored m e r i d i o n a 1 e 



2 With eight filaments 



a Pupa 4.5mm long; Arizona species. Pupa described* in 

 Am. Ent. Soc. Trans, p.45. 1S03. 



h Less than 4mm long; eastern species 



venustum, var. piscicidium 



3 With nine filaments. Pupal case like that on pl.35, figj5. . .p i c t i p e s 



4 With 10 filaments var. a of venustum 



5 With 12 filaments. Pupal case [pi. 35, fig.5]. From Santa 



Cniz mountains, CaL [p.3S7] 



6 With 16 filaments vittatum 



7 With 24 to 48 filaments [pl.33, fig.lO] pecuarum 



8 With 60 or <nore filaments hirtipes 



Imagines 



1 Ground color of the thorax and abdomen deep yellow (2) 



Gi-ay or black; its liairs may be pale (3) 



2 " Femora with black tip, length of fly 2mm." Mexico, .ochraceum 

 " Femora without black tips. Length 3 to 4.5mm. Rocky 



mountains " f u 1 v u m 



3 Hind tarsi with its basal joint partly j'ellow; legs bicolored (9) 



Hind tarsi unicolored2 (4) 



4 Halteres dusky; thorax not striped (5) 



Halteres white or yellow; the female with striped thorax and 



bifid tarsal claws (6) 



5 Body black; the female with dense yellow pile, her tarsal 



claws simple; the male with dense hair on the legs, his 

 tarsal claws trifid. The wing with its radius three 



branched. Length 3 to 4.5mm ..........hirtipes 



" Body gray, legs reddish gray, feet black; length 3mm." 

 This is said by Mr Coquillett to be the siame as pecua- 

 rum Riley in venustum 



6 Males, eyes contiguous (7) 



Females, eyes separated by a distinct line (8) 



'In order to see this it will be necessary to examine nearly mature speci- 

 mens and perhaps to draw them from their pupal skins. 



2The male of p i c t i p e s sometimes has legs nearly unicolored; it is 

 however included in the preceding section. 



