18 SOUTH AMERICAN TIPULIDAE 



ward. Two apical appendages, the outer appendage (b) fleshy, slender at the 

 base, gradually enlarged into the flattened tip and here provided with numer- 

 ous long hairs, the dorsal margin produced into a single subappressed sharp 

 chitinized spine; this appendage is bent inward and the flattened exj^anded 

 tips almost meet on the middle line; the inner pleural appendage (c) fleshy, bent 

 at the middle, the tip directed dorsad. The penis-guard (d) is represented by a 

 central subfleshy lobe with the tip constricted and ending in an obtuse point 

 beneath, on either side with a very slender, chitinous hook whose tip is bent 

 ventrad. 



The female is quite as in the male, the antennae a little shorter but still 

 longer than is usual in this genus of flies ; lateral margin of the praescutum whit- 

 ish; a more or less conspicuous white band on the pleura beneath the brown 

 pleural stripe; ovipositor with the valves long and slender. 



Habitat. — Peru. Holotype, cf, Lima, Peru, altitude 500 

 feet, July 29, 1914 (Parish coll.). Allotype, 9, topotypic; 

 August 19, 1914. Paratypes, 10 cf', 9, topotypic, July 29, to 

 August 31, 1914. 



The three related species, cognatella O. S., delicata Alex, and 

 the present form may be separated by the following key: 



1. Wings hyaline or nearly so; Sc short, ending far before the origin of the 



radial sector 2 



Wings tinged with yellow; Sc long, ending nearly opposite or just before 

 the origin of the radial sector. (Eastern United States) 



cognatella O. S.^ 



2. Mesonotum broadly edged with yellow in front and on the sides; two 



brown pleural stripes. (Guatemala) delicata Alex.^s 



Mesonotum without a conspicuous yellowish margin; a single broad brown 

 pleural stripe. (Peru) jejuna sp.n. 



The members of the cognatella group have the following com- 

 mon characters: Cell R2 of the wings large, vein Ro being oblique; 

 cell 1st Mi open by the atrophy of the outer deflection of Nz] 

 basal deflection of Cui at the fork of M; basal segments of the 

 antennae yellow. 



Gonomyia (Gonomyia) velutina sp. n. 



Head gray; pleura with a prominent white longitudinal band; wings sparsely 

 spotted with brown. 



Male. — Length, 5.3 mm.; wing, 7-7.4 mm. 



Female. — Length, 6.5 mm.; wing, G.8 nun. 



Rostrum dark brown; palpi dark brownish black. Antennae dark brownish 

 black, rather short, the segments of the flagellum oval to shghtly elongate- 

 oval. Head dark brown, dusted with gray. 



2^ 1859. cognatella Osten Sacken, Proc. Acad. Nat. Sci. Phila., p. 230, pi. 

 4, fig. 17. 



2" 1913. delicata Alexander, Proc. U. S. Nat. Mus., xliv, p. 506. 



