NYRIDELA; LEUCOTMEMIS. By Dr. M. Draudt. 
69 
27. Genus: UTyridela Lucas. 
This genus contains only 2 very similar, large, robust species with hyaline, broadly black-margined 
wings with a black median band. The erect palpi project but little beyond the vertex; in the d a large valve 
covers the ventral side of the basal abdominal rings. On the forewing the lower median vein rises near the 
lower cell-angle and is strongly curved downwards, the upper median vein and the 2 lower radial veins all rise 
separately from the lower cell-end. On the hindwing the discocellular runs so very obliquely that the cell does 
not become visible. 
N. xanthocera WJcr. (9 k). From the similar chalciope Him. this species differs by the quite yellow xanthoceru 
antennae, the blackish-blue forehips, and the metallic-blue colour being less prominent on the abdomen. Widely 
distributed in Central America, so in Mexico, Guatemala, Costa Rica, and Panama. 
N. chalciope Hbn. (= acroxantha Perty) (9 k). Very similar to the preceding species from which it chalciope. 
differs by the black antennae being yellow only at the tips, the white forehips and the metallic bluish green 
spots being more prominent on the abdomen. It flies not only in Colombia (Bogota) and Brazil, but also 
in Cuba. 
28. Genus: l<eiicotiiiemfs Btlr. 
Exactly like Cosmosoma, but the upper median vein rises in common with both the lower radial veins 
from the lower cell-end, or at least shortly before it, but never separated so far as in the following genus. The 
species are mostly distinguished by a broad, black middle band of the forewings. 
L. dorsalis Wkr. (15 a). Black-brown; palpi and stripes on the shoulder-covers orange; the abdomen dorsalis. 
exhibits broad orange lateral stripes; of the same colouring is the underside. The black-brown forewings exhibit 
hyaline stripes in and below the cell and a yellowish hyaline spot behind the cel! between the upper median 
vein and the lowest subcostal; the veins crossing it are yellow. Hindwings black-brown, at the base orange, 
behind the cell with a yellow hyaline, orange-veined spot. Expanse of wings: 20 mm. Amazon. 
L. varipes Wkr. (= albiventris Wkr., syrphiformis H.-Schdff.) (15 a). Head and thorax black, forehead varipes. 
and collar bordered with white. Legs white and brown with yellow tarsi. Abdomen carmine with a black apex, 
and white and brown subdorsal spots on the first segment; venter white. Wings hyaline, towards the margins 
dusted with brown, the veins, costal and inner margin being brown in the yellow in the $, with a very large, 
brown discal spot being confluent with the inner-angular spot. Expanse of wings: 24 mm. Amazon. 
L. margariphera Btlr. (12 m) is a large, beautiful species with a black head and thorax; on the vertex margari- 
and collar blue spots; on the shoulder-covers a small, orange-yellow spot; the abdomen is carmine; the first p]>c 
segment black with subdorsal blue dots and orange-yellow lateral spots; on the other segments subdorsal, 
opalescent, whitish spots; the 3 last rings are black, with metallic-blue spots; the underside is yellowish-white. 
The wings are faintly yellowish hyaline; veins, costal and inner margins yellow; a metallic-blue spotted discoidal 
spot, apical and inner-angular spots are black. Amazon (Para). 
L. pleuraemata Hmps. (12 m). Black-brown, base of the palpi white; spots on the collar and broad pleurae- 
lateral stripes on the abdomen are carmine ; on the first abdominal ring the latter are yellowish ; hips and ventral mala 
side yellowish-white. The wings are hyaline with black-brown margins, median band and apical spots. Brazil 
(Sa. Catharina). — v. paranensis Schrottky (26 k), from Paraguay and Argentina which may be a species of paranensis 
its own, is. considerably smaller, the palpal base being red instead of white, the hips and venter of a pure white, 
not yellowish. Flying on compositae. 
L. tenthredoides Wlkr. (12 m). Head black, on the vertex with metallic-blue spots, forehead downward tenthre- 
white; collar black and blue; thorax orange, shoulder-covers bordered with black; abdomen orange, the last 
3 segments black and blue spotted, in the $ with a black spot on the preceding ring. The wings are hyaline, 
the margins, median band and apical spot black; at the base of the costal margin a blue spot; subcosta, inner 
margin and the veins behind the median band orange; base of the hindwing orange. Distributed from Guiana 
to the Amazon. 
L. hemileuca Btlr. (12 m) is allied to the preceding species from which it differs by the absence of hemileuca. 
the metallic-blue spots on the base of the forewing and at the end of the abdomen; it is also considerably smaller. 
The thorax is black, only the basal half of the shoulder-covers is orange; abdomen orange, the two last segments 
black, on the preceding segment a black spot; underneath whitish. In the $ the black median spot of the forewing 
remains separated and hardly touches also the inner margin, whereas the $ has a developed median band. 
Amazon. 
