POLY STROMA; NYCTEROSEA; ORTHOLITHA. By L. B. Pkout. 
8() 
at the fold. The yellowish tinge on hindwing and underside will aid recognition. Pectinations quite rudi¬ 
mentary. A high altitiide s])ecies (24()(t m and iqwards), described from Kilimandjaro. 
iricnkda. X. trientata Warr. ($ = asteria Fawcett) (9 c). Very easy to distinginsh from exorista, its nearest 
ally, by the much more uniformly coloured ])roximal area of the forewing and es])ecially by the vinaceous- 
cinnamon suffusions of the distal area beneath, which show also on that of the hindwing above. Nandi 
Country and Kikuyu Escarpment. 
c.rDriaia. X. exorista Prout (9 c) was formerly confused with the Indian saturata Giien., hut is more variegated 
both almve and beneath. (J genitalia very distinct, the apex of the valve not bifurcate, the saccus less 
narrowed, the cornuti less numerous. In both species the cJ antenna is merely sid)dentate with pairs of short 
fascicles. Widely distributed from Abyssinia and Uganda to the Cape, the type from Natal. A from 
Banso Mountains, Canieroons, GOOO feet, in my collection, has the band very dark and rather narrow, the 
sid)apical patch somewhat extended, and perhaps represents a race. 
iHitalatu. X. (?) natalata Walk. (— polyacmaria Mah., vorax Strand) (9d). Closely allied to stellata Guen. of 
America and the Atlantic Islands, scarcely more than a sidrspecies. On an average larger, but very variable. 
iSystematic position doubtful, the genitalia in several details very dissimilar to those of true Xanthorhoe: unciis 
shortened, bilobed, a free sacmdus arm, the calcar undeveloped. The somewhat shortened anastomosis of the 
costal vein of the hindwing, as well as the pattern, might associate it with Gamptogramma, but there is little 
to siipport this view. Distributed nearly throughout continental Africa soiith of the Sahara. The larva has 
nthrithukt. been recorded as very abundant on Bougainvillia in Togoland. — rubfitincta Hmps., from Sokotra, has the 
postmedian line more strongly outbent in the middle, the succeeding space somewhat warmer brown, the 
constdlata. distal area beneath strongly dark. — constellata Warr., from Mauritius, is a dark form, with the white lines 
slight, punctiform. Examples from Madagascar are perhaps intermediate between this and the name-type. 
3. Genus: l*olystroma Warr. 
Characters of the last section of Xanthorhoe antenna fasciculate), exce])t that the G has a hair-pencil 
on the forewing l)eneath, placed nearly as in Eustronm, etc. Perhaps better regarded as a further section of 
Xanthorhoe. Besides the African genotype it only includes adumbrata Koll. (= fuscigrisea Hnipsn.), from the 
N. . Himalayas. 
P. subspissata Warr. ($ = brunneitrames Front) (9d). Generally larger than X. exorista, especially 
in the $ (here figured), slightly longer-winged, the forewing with better developed cell-mark and oblicp\e dark 
apical dash (behind the whitish dash), etc. Natal (loc. typ.), Transvaal and Cape CVlony, also (race?) on 
Madagascar. 
4. Genus: l^ycterosea Hulst. 
This genus, which has generally l)een called PercnoptUota Hulst (w merged in Orthonania lib., differs 
from the last section of Xanthorhoe and from Oithonama in having the 1st median of the hindwing connate 
or nearly always stalked, not (as in them) separate. The sinuous border of the hindwing, the strong sexual 
dimorphism and the general habitus, as well as the genitalia, further separate it from Xanthorhoe. Only the 
cosmopolitan ty])e-species is generally known, though Me. Dunnough has se])arated off a close ally in Canada. 
obsttputu. N* obstipata F. (= fluviata Hbn.., gemmata Hbn., angustata Haw., albicinctata Haw., lapillata Guen., 
baccata Guen., inconspicua Warr., brunneipennis Hulst) (Vol. 4, 9 e). We have already given an account of 
this, the most widely distributed of all the Geometridae, in Vol. 4, p. 228, with characteristic figures of both 
sexes. Although variable, it is always easy to recognize. FABRicirs described it from North Africa, but its 
discufa. I'ange extends throughout the continent. — ab. discata Warr. (9 d), from Natal, is a form with the antemedian 
band ill-developed, the postmedian line strengthened. 
5. Genus: Ortliolitlia Him. 
Very near Xanthorhoe, perhaps intergrading (com])are X. conchata), in the more easily observed charac¬ 
ters scai’cely differentiable except that the costal margin of the hindwing is considei'ably longer than the himl- 
margin of the forewing. The true Ortholitha of the Palaearctic region is distinguished also by some features 
of the genitalia and, according to Walther, the maxillary ])alpus; l)ut these characters have not yet been 
tested on the African s])ecies. Hindwing generally much more weakly marked than forewing. 8ome species 
are included in which the G antenna is simply ciliated. 
A. Antenna of G p e c t i n a t e. 
