140 MEMOIRS NATIONAL ACADEMY OF SCIENCES. vol. xii, 



Fore wings rather shorter and broader, and the hind wings broader and rather more rounded 

 at apex. The hind wings extend as far as the end of the abdomen. The venation in general 

 is as in Hemileuca, but with the notable difference from any other genus of Hemileucidae that 

 vein II 5 arises rather far from the origin of IIL., far from the discal veins; the latter also are 

 oblique, especially the posterior one. Hind wings with the discal veins very oblique, the other 

 veins much as in Hemileuca. 



Markings: Wings all pale, tending to ochreous whitish, the veins being dark, distinct; no 

 discal spot and no bars, only a submarginal brown line common to both wings. 



There are no long flattened hairs on the thorax. 



The type of this genus is Hemileuca venosa Walker. 



The species is confined to northeastern South America, M. venosa occurring in Venezuela 

 (Caracas) and Colombia (Bogota). My example was compared with Walker's type in the 

 British Museum, and the localities mentioned are from the labels in that museum. 



MEROLETJCA VENOSA (Walker). 

 Plate LII, fig. 7. 

 HemiUuca venosa Walker, Cat. Lep. Het. Br. Mus., VI, p. 1319, 1855. 



Imago. — One <? . Head and body Vandyke brown. Prothoracic collar dull ochreous. 

 Both wings uniformly pale ochreous whitish, but the veins contrast with the ground color in 

 being brown, as is the fringe. No discal spots, though there is a slight tendency for the pale 

 ochreous scales to be thicker over the discal veins. A slightly sinuous submarginal diffuse 

 brown line parallel with the outer edge of both wings; the line is a little wider on the hind than 

 fore wings. Hairs on the fore tibiae somewhat yellowish. 



Beneath as above, costa of fore and hind wings a little more ochreous than the rest of the 

 wings. End of the abdomen reddish, much as in H. maia. 

 Expanse of fore wings, o* 49 mm. 

 Length of fore wing, S 25 mm. 

 Breadth of fore wing, d 1 13 mm. 

 Length of hind wing, <? 21 mm. 

 Breadth of hind wing, S 15 mm. 



HELICONISA Walker. 



[Heliconisa Walker, Cat. Lep. Het. Brit. Mus., VI (1855), p. 1333.] 

 [Type B. impar Walker. =Nyctemera pagenstecheri Geyer.] 



Imago. — <? . Head quite wide in front; vestiture thick and full, much as in Pseudohazis; 

 eyes not very large. Antennas of o* just as in Hemileuca and Pseudohazis, quite long and 

 moderately wide, pectinated to the tip; the branches curved upwards near the base; only a 

 single pair on each joint, the distal ones wanting. Palpi scarcely distinguishable from the 

 front, weak, drooping, the hairs long and irregular; the joints not distinct, much as in 

 Pseudohazis. Thorax wooly and shaggy. 



The wings are perfectly transparent so that every vein is naked, the scales being confined 

 to the edge of the wings, where the squamation is thin, but naturally thickest and densest 

 along the costal edge. No discal spots or scales. Fore wings moderately pointed at the apex, 

 which is not quite so sharp, while the outer edge is not so oblique as in Pseudohazis. Hind 

 wings rather long, longer than in Pseudohazis and rounder on the inner angle. 



Venation: [Dr. Dyar finds that veins 9 and 10 (III 3 and III 2 ) of the fore wings are absent. 

 A sketch supplied by him represents 7 and 8 (III 5 and III 4 ) present, joining nearer to apex 

 of cell than to apex of wing; 6 (IV) arising from upper corner of cell; 5 (IV 2 ) from middle of apical 

 side of cell, midway between 4 and 6; 3 (V,) arising from lower side of cell, as far from 4 as 4 

 is from 5.] 



Fore legs provided with a tibial process or elongated sack, about three-fourths as long as 

 the tibia itself. Abdomen rather slender, not reaching so near the inner angle of the hind 

 wing as in Pseudohazis. 



