DIDYMA.—NEOPTERA. 165 
17. Didyma pavida, sp. n., 3 9. 
Blackish ; thorax cinereous, with black lines ; front borders of the second and third abdominal segments with . 
scarcely any white reflections ; no discal macrochxta. 
Length 4:5-5°5 millim. 
Head blackish, with white reflections ; front narrower than the eyes; frontal band black, narrower than the 
lateral portions; frontal bristles descending as far as the end of the second antennal joint; eyes distinctly 
pilose. Antenne black; third joint four times as long as the second ; arista thickened to the proximal 
half. Proboscis black; palpi pale rufous. Thorax blackish ; thoracic dorsum with a cinereous tomentum 
and four black lines, which are less distinct behind the transverse suture; scutellum black. Abdomen 
ovate (a little broader in the female), shining black ; second and third segments with some whitish reflec- 
tions on the front borders; all the segments with marginal macrochete. Legs black; middle tibic with 
some long bristles ; hind tibie outwardly with bristles of unequal length ; foot-claws and pulvilli short in 
both sexes. Tegule greyish-white. Wings greyish-hyaline; small cross-vein on the middle of the discal 
cell; third vein slightly curved before its end; apical cross-vein straight, only a little concave near the 
tip; posterior cross-vein straight ( g ) or somewhat curved ( ? ), inserted beyond the middle between the 
small cross-vein and the curvature of the fourth vein. 
Hab. Mexico, Venta de Zopilote 2800 feet, and Amula 6000 feet, both in Guerrero 
(H. H. Smith). 
A male and a female specimen. 
18. Didyma volucris, sp. n., 3 ?. 
Blackish ; thorax cinereous, with black stripes; abdominal segments with whitish front borders; no discal 
macrocheete on the intermediate segments ; palpi rufous. 
Length 6—7 millim. 
Front cinereous, slightly prominent, as broad as the eyes; frontal band black, narrower than the lateral 
portions, sometimes inconspicuous in a grey reflection ; frontal bristles descending to beneath the second 
antennal joint ; face and cheeks whitish ; eyes thinly pilose. Antenne black; second joint with short 
bristles ; third joint five times as long as the second; arista thickened to the proximal half. Proboscis 
black, the terminal lips with yellow hairs; palpi rufous. Thorax cinereous, with four black stripes, the 
outer stripes interrupted at the transverse suture; scutellum black, with the hind margin grey. Abdo- 
men conical, black ; second and following segments with white front borders (the white colour laterally 
more extended) and with long marginal macrocheetee ; in the male the anal segment has a few macro- 
cheetee on the disc and several round the anus (the discal ones are absent in the female). Legs black ; 
middle tibiz with some long bristles ; hind tibie outwardly with bristles of unequal length ; in the male 
the foot-claws and pulvilli are a little longer than in the female, the pulvilli yellow. Tegule whitish. 
Wings dilute brownish (¢) or greyish-hyaline (@); small cross-vein a little before the middle of the 
discal cell; apical cross-vein straight or nearly straight ; posterior cross-vein slightly curved inwards. 
Hab. Mexico, Venta de Zopilote 2800 feet, and Omilteme 8000 feet, both in Guer- 
rero (H. H. Smith). 
A male and a female specimen. 
NEOPTERA, gen. nov. * 
Body short and broad. Head hemispherical; front narrowed behind; frontal band inconspicuous; frontal 
bristles reduced to short hairs ; face perpendicular; oral margin not prominent ; cheeks rather broad ; no 
distinct vibrissee, but the underside of the face with many weak hairs. Eyes bare. Antenne short; 
* yéos (singular), rrépov (wing). 
