DEXIA.—ACRONACANTHA. 243 
1. Dexia genuina, sp.n., 3 2. 
Cinereous ; thorax with three blackish stripes; abdomen with blackish reflecting spots ; antenne, palpi, and 
legs rufous, the tarsi black. 
Length 5°59 millim. 
Head light cinereous, the front with black, the cheeks with rufous reflections ; front of the male slightly 
narrowed behind, on the vertex as broad as the eyes, that of the female scarcely broader; frontal band 
brownish-rufous, as broad as the lateral portions ; vibrissee inserted at a little distance above the oral 
margin, beneath them several other bristles of nearly the same length ; occiput swollen in its lower part. 
Antenne rufous; second joint prominent; third joint slender, three times as long as the second, 
somewhat infuscated ; arista thickened at the base. Proboscis rufous, especially at the base and at the 
terminal lips; palpi small, pale rufous. Thorax and scutellum cinereous ; thoracic dorsum with three 
ill-defined blackish stripes. Abdomen elongate-oval, cinereous, with dark reflecting spots, which in the 
male form a blackish dorsal stripe, blackish hind borders to the segments, and sometimes two elongate 
trigonal spots (laterally of the dorsal stripe) on the second and third segments; in the female the 
abdomen has a greyish tint and the reflecting spots are more irregular, a black dorsal stripe, however, 
being visible; only marginal macrochete are present ; in the male the ventral surface is densely haired. 
Legs, including the coxe, rufous, the coxe with grey tomentum; the tarsi black; in the female the 
femora have on the upperside a blackish stripe—this is sometimes so extended on the front pair that 
they might be described as black with a rufous tip, while on the middle and hind femora it is extended 
to a circle before the end ; foot-claws and pulvilli slightly elongate in the male, the pulvilli yellowish- 
grey. Tegule yellowish-white. Wings brownish-grey ; small cross-vein under the end of the first vein 
and on the middle of the discal cell; curvature of the fourth vein in one of the male specimens with a 
short appendage, this being wholly absent in the others; apical cross-vein deeply concave ; posterior 
cross-vein nearly straight. 
Hab. Mexico, Omilteme in Guerrero 8000 feet (H. H. Smith). 
Two male and three female specimens. 
ACRONACANTHA, gen. nov. * 
Head (seen from in front) higher than broad, narrowed below; face nearly perpendicular, not carinated ; 
antennal grooves deep; oral margin not prominent ; cheeks broad, their lower portion equalling more 
than the half the longitudinal diameter of the eyes ; vibrissal swellings distinctly convergent ; vibrisss 
inserted at some distance above the oral margin. Eyes bare. Antenne short, slender, inserted above a 
line drawn through the centre of the eyes; third joint longer than the second ; arista short-haired, 
Proboscis short and thick; palpi cylindrical. Abdomen elliptical; macrochete long, only at the 
hind margin of the segments. Legs slender, with scattered bristles ; tarsi longer than the tibia. 
Wings broad, with a costal spine; apical cell opened a little before the wing’s tip; curvature of the 
fourth vein angular and with a short appendage ; posterior cross-vein in the middle between the small 
cross-vein and the curvature of the fourth vein ; sixth vein reaching the hind border of the wing. 
1. Acronacantha nubilipennis, sp.n.¢. (Tab. V. figg. 12; 12a, head.) 
‘Blackish ; front borders of the abdominal segments grey ; antenne rufous, with black tip; legs partly rufous ; 
wings clouded with brown. 
Length 7 millim. : 
-Face and cheeks yellowish-white, with reddish-brown reflections; front blackish, Antenne rufous, the 
. apical half of the third joint and the arista blackish ; third joint three times as long as the second. 
Proboscis black, with the terminal lips rufous. Thorax, scutellum, and abdomen black, with some grey 
tomentum ; thoracic dorsum without distinct stripes ; front borders of the second and following segments 
* dxpoy (margin); dxav0a (spine). 
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