250 BRITISH GUIANA TIPULIDAE 



Thoracic notum light brown, dorsal stripes not apparent; the postnotum 

 darker brown medially. Pleura rather pale, brownish yellow. Halteres 

 brown, the extreme base pale. Legs with the coxae and trochanters rather 

 bright yellow-; femora brown, only the tips slightly darkened; tibiae brown, 

 the tip narrowly dark brown; fiist tarsal segment very pale, almost white, 

 remainder of the tarsus brown. Wings with a pale yellow suffusion, the cos- 

 tal cell brighter yellow; brown clouds at the origin of Rs, fork of flj+j and 

 the radial cross-veins and deflections of veins narrowly and indistinctly 

 seamed with brown; cephalic half of the long cell /f: infumed. Venation: 

 (see plate IV, fig. 9) Rt tending to atrophy, its tip fused with Ri at the 

 wing-margin. 



Abdominal tergites light brown, beyond the third segment darkening 

 into a deeper browTi; stemites yellow, the apical segments darker. 



Habitat. — Bartica, Januarj' 30 to February 21, 1913. 



Holotype, cf, Bartica, February 21, 1913. 



Paratype, cf, topotypic, January- 30, 1913. 



This form is the smallest of the described species with the 

 exception of obliteratus Alexander; the forms may be separated by 

 the appended key. 



A Key to the Species of Psakonius Enderlein 



1. iEs entirely atrophied; cell 2nd Ri entirely obliterated. (Paraguay) 



abnormis Alexander" 



R2 present, at least basally; the tip may be fused with iJi at the wing 



margin 2 



2. Ri fused with Ri at its tip so that cell 2nd Ri is very tiny, pointed at its 



distal end which does not attain the wing-margin 3 



R2 free for its entire length, running sub-parallel to fii and Rs so that 

 cell R2 is long, slender, its distal end at least as broad as its prox- 

 imal end and attaining the wing-margin 4 



3. Smaller; wing of male less than 12mm. ; wing suffused with brown; body 



coloration dull black; antennal flagellum black, the scape orange. 



(British Guiana) ohlileralus Alexander'" 



Larger; wing of male over 12 mm. ; wing pale yellowish; body coloration 

 orange-yellow; antennal flagellum brown, only the first segment 

 orange. (British Guiana) pygmaeus sp. n. 



4. Wings light yellow or brownish yellow ; body coloration ochraceous yel- 



low, the markings rather indistinct. (Guiana; Brazil) 



obscurus Fabricius" 



Wings dark brown; body coloration brown, the marking dark brown. 



(British Guiana) fuscipcnnix sp. n. 



" 1914. abnormis Alexander, Ent. News, xxv, 211, pi. ix, fig. 9 (Lecleria). 

 *o 1913. obb'icrata Alexander, Proc. U. S. Nat. Mus., xliv, 494 (Lecleria). 

 " 1805. nbscurn Fabricius. Svst. Antl.. 27 (Tipuln). 



