PHILO SAMI A, ROTHSCHILDIA. By Dr. M. Draudt. 
715 
The habits of the American Saturnidae are chiefly the same as in the other faunal regions, fn the real 
tropic belt itself presumably all are more or less nocturnal, both the sexes being taken on the lantern at night. 
The farther one proceeds to the north or south, the more the fly in daytime, as for instance in North 
America the species of Pseudoliazis and Hemileuca which are coloured like butterflies, and in Southern Chile 
particularly the conspicuously variegated Polythysana the GS of which keenly swarm about in search of the 
lazily seated 9 $- Izquierdo has recently made studies on the attractive force of the 9 ? of P. edmondsi ; these 
insects behave exactly as for instance our Orgyia- species are known to do. since a great number of $$ may 
be allured by a single virgin female. 
Moreover, the Heliconisa occurring in Southern America are especially remarkable for the great sexual 
dimorphism, the $$ with their hyaline wings dashing along in the sunshine and tracking the enormously stout 
dark-coloured females which are sitting hidden in the grass. In a very charming way J. F. Zikan has informed 
us of the innumerable $$ of H. pagenstecheri whirling about in the air like the drift of large snow-flakes. Very 
differently coloured and marked are also the sexes of some Dirphia , such as those of the tarquinius-group, as 
well as some species of Autorneris such as flexuosa or even the well-known io, many species of Copaxa, and 
especially among the Syssphinginae a great many species of Eacles and Githeronia. The Syssphingidae provided 
with a rudimentary proboscis very likely do not take up any food as imagines, whereas the Oxytenidae, which 
have a well developed proboscis and look exactly like Geometrids, probably do so, although we are hardly 
cognisant of their habits. 
I. Group. Cell of forewing open ( Attacinae ). 
1. Genus: Philosamia Grt. 
Regarding this genus being quoted as Sarnia in Vol. II, p. 212, we may refer in general to the above 
mentioned place as well as to Vol. X. p. 503, where the genus and species has been dealt with at large. We 
merely repeat here the presence of a small proboscis without any function: antennae of $ and 9 pectinate; in 
the latter sex hardly shorter. Abdomen above provided with several rows of woolly tufts; both wings with 
a crescentiform hyaline spot. Neuration otherwise not peculiar. The only species to be considered originates from 
the Indian fauna from where it was acclimatized both in Europe and — since 1861 - in North America. 
Ph. cynthia Dru. This universally well-known lepidopteron with its ground-colour varying between cynthia. 
loamy yellowish and olive green or brown has been figured so very often that we only refer to the figures in 
Vol. II pi. 33 a and Vol. X pi. 52 c. The American specimens which were named — advena Pack, are not very advena. 
large and, particularly in the female, they have a thickset shape with obtuse wings, the colour being never 
very bright green. Especially in the region of the Atlantic coast the form is rather common in the neighbourhood 
of large towns. The white-hued, lighter or darker green larva exhibits 6 rows of bluish fleshy thorns and 
chiefly lives on Ailanthus, Ilex, Sambucus, but besides also on nearly all foliage-trees and shrubs. The silk 
gained from the cocoons is of little value, coarse, and cannot be reeled off but only carded. — The larva could 
be bred by the coupling of cynthia with promethea 9, it is said to have exactly corresponded with the larva 
of promethea. According to Strecker, this hybrid has also been observed as imago in nature and is said to 
combine the colour of cynthia with the discal marking and the shape of the wings of promethea -9- According 
to the same author, the male obtained by breeding, however, is almost exactly like a blackened promethea- 9 . 
2. Genus: Koihschildia Grt. 
The representatives of the palaearctic genus Attacus in America are a very homogeneous well 
characterized group of partly closely allied and often hardly differentiated species, particularly because the 
frequently wrong use of the names has caused dreadful mistakes and confusions; we have tried to disembroil 
as much as possible, and by the aid of Er. Jordan and Sohaus, we believe to have attained some clearness in 
the right use of the names. They are large lepidoptera, the apex of the forewing, especially in the often 
somewhat falciform, though roundly produced, with a more or less tiiangular or. preferably in the 99> oval 
h}mline spot on all the wings, situate between 2 characteristic transverse lines. Palpi short, antennae in both 
sexes pectinate, though shorter in the 99 - On the very broad forewing veins 2 and 3 rise rather distantly 
separated, the cell is open as in all the genera of this subfamily. Hindwing especially in the GG often extra¬ 
ordinarily long so that the comparatively slim abdomen does not extend to the centre of the inner margin, at 
the distal margin often somewhat concave, in the 9$ more rounded and shorter. Larvae stout, cylindrical, 
with short starlike arranged hairs on knob-shaped tubercles, not unlike the palaearctic larvae of Saturnia, 
or also without tubercles. They pupate in a frequently pear-shaped cocoon. 
