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 expanded 
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 
\Mngs 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.^^ 
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 R2 being oblique; 
cell 1st M2 open by the atrophy of the outer deflection of Ns; 
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, 6.8 mm. 
Rostrum dark brown ; palpi dark brownish black . Antennae dark brownish 
black, rather short, the segments of the flagellum oval to slightly elongate- 
oval. Head dark brown, dusted with gray. 
^^ 1859. cognatella Osten Sacken, Proc. Acad. Nat. Sci. Phila., p. 230, pi. 
4, fig. 17. 
^'^ 1913. delicata Alexander, Proc. U. S. Nat. Mus., xliv, p. 506. 
