Publ. 23. VI. 1926. 
SATURNIIDAE. By Dr. A. Seitz. 
497 
14. Family: Saturniidae, Emperor-Moths. 
On reviewing vast numbers of Saturniidae we notice that the boundaries which one has tried to draw 
between the different genera and even groups of genera, disappear. The falcate shape of the wings does not 
only vary in the sexes, so that the AS almost invariably exhibit more projecting apices of the forewings than 
the $$ belonging to them, but it also varies in the races and even individually. The same is the case with 
the remarkable occurrence of tails on the hindwings, which we discover to be of a monstrous length in the <$<$ 
of Actias (Argema ), but much shorter in the and in certain forms (aliena. artemis) moulded into a tooth- 
like form. In the Coscinocera the are without the long ensiform tails, whereas species of the genus Attacus 
already show an enormous prolongation and even distortion of the hindwings, thus the two genera which are 
similar in structure approach each other in the separating moments. By domestication and transplantation, 
forms exhibiting the abdominal dorsum set with flocks arranged in rows evolved into forms with streaked, and 
even unicoloured, unmarked abdomina, so that not even these distinctions can be used for the separation of 
groups or even of species. 
The Saturniidae undoubtedly represent a phyletically old group. There is hardly any other group to 
be found among the Heterocera adhering to certain characteristic marks with such unfailing persistency as the 
Saturniidae adhere to the centre spot which, mostly modified into an eyes pot, lies between an antemedian and 
a postmedian transverse stripe. From the great consistency exhibited in this mark, even in different genera, 
which are already beginning to deviate structurally, we may assume that external motives could not bring 
about a great variety of shapes among the Saturniidae. Actias dubernardi, Platysamia cecropia, Aqlia tau, or 
Saturnia pyri wear their own unborrowed clothes, and it seems to us that with the Saturniidae lack even those 
cases which are not uncommon in other old families, in which single formations of the apices exceed beyond 
the average of those of the other members of the family and have been transformed into more variable shapes. 
In the Brahmaea which are closely allied to the Saturniid family, we even notice the strict adhesion to such 
a complicated and most curious pointing that the members of a species hardly differ from one another, and 
those of a genus but very slightly, although in most of the individual specimens the marking on the left and 
right sides differs in detail. Thus adhesion to an entirely original colouring is charcteristic of the Saturniidae 
and their nearest allies. 
Our assumption of the great phyletical age of the Saturniidae ist also in accord with the peculiarities 
of their range. Even the species themselves are mostly very widely distributed, but still more so the genera, 
resp. their colourings. The resemblance of the purely Asiatic Actias selene to the purely American A. luna is 
just as remarkable as the recurrence of the image of Attacus atlas in the exclusively American Rothschildia of 
which the larvae as also the structure exhibit a much greater disparity than might be expected from their great 
habitual resemblance. Neither mimicry nor adaptation can have effected this external likeness, but probably 
only a highly pronounced impulse of development in a very positive direction. 
As in most of the old lepidopteral families, adaptation to surroundings is highly developed in very many 
cases. In fact, it is rather difficult to discover an Actias sitting amongst the leaves of bushes. Only freshly 
hatched specimens resting on trunks or posts in order to stretch their wings are more easily found. In a valley 
of Ceylon, where 1 daily collected without ever seeing any Actias, one day, after the leaves of the small trees had 
been singed black by a plantation-fire, I was sursprised to see the great number of Actias selene which sat in the 
burnt foliage, now visible from afar as so many green spots their protective colour rendered ineffective. The 
resemblance of some Antheraea to a dry leaf is hardly less striking than that of the butterfly Kallima which is 
everywhere quoted as the best example of protective similarity. The imitation of the middle rib of the leaf by 
the white stripe extending from the left apex to the right in the resting lepidopteron becomes more plastically 
pronounced by unilateral shading, and in Cricula we even see at that place, where the fallen leaves usually rust 
X 62 
