DREPANIDAE. Introduction by Dr. A. Seitz. 
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9. Family: Drepanidae. 
It is rather difficult to make general remarks about the propinquity and range of the Drepanidae, 
since their delimitation from the other families is very uncertain. Those reckoning the American Cicmnus in 
with the Drepanidae (Kirby) will discover a good transition to the Saturnidae, at least if we remain in the 
American Fauna; but if the Mimallonidae with their larvae living in cases that are open on both sides are 
exempted and treated as a separate family, this connection is torn asunder, at least for the American Fauna, 
and in this case the family would be removed more to the Thyrididae exhibiting several resemblances in the 
neuration (cf. Strand, Yol. 2, p. 195, and Warren, Vol. 10, p. 444). 
The thorough elaboration of the Mimallonidae, in contrast with our former poor knowledge, easily 
shows how very appropriate and natural their separation from the Drepanidae is. In the American Fauna we 
then only need yet to consider the relations of the Drepanidae to the Oxyteninae which are only represented in 
the New World. In fact, the habitual resemblance between the American Therinia and many palaearctic 
genuine Drepanidae is by no means limited only to the light colour of the wings or to their shape. By the 
proportion of the uncommonly broad and large wings to the tiny abdomen which is by far exceeded by the 
anal angle of the hindwing, the prominently marked and coloured apex on the hindwing of many Drepanidae 
( Macrocilix, Seu-a), the frequent exterior resemblance to Urapteryx (in Ditrigona), and other accords with 
distantly remote Geometridae, which can by no means be due to mimicry or exterior conditions (as for instance 
Auzata semipavonaria with Ripula mahometaria; Canucha with Oxydia; Auzata superba with Problepsis etc.), 
the South-American Oxyteninae are, to a certain degree, parallelled with the Drepanidae. 
In addition there is the curious zoogeographical fact that the Drepanidae are entirely absent in the 
whole of South America, but represented there, to some extent, by the habitually similar Mimallonidae. There 
prevails an unmistakable exterior resemblance between many of these Mimallonidae and the Ore/a-species 
from the groups of O. variegata, dissimilis, cervina, castaneata, jaspidea etc., and also here we find the general 
law that certain formations being opportune for some reason or other develop from frequently heterogenous 
branches of their pedigree, at various places of our globe where certain conditions of life coincide, as for instance 
the Geometrid Carthaea saturnioides in Western Australia, where no Saturnia occur. 
We may, however, readily assume the probability of close relations of the Drepanidae to the family 
of the Notodontidae. There is no doubt that several branches of the Notodontidae have developed in various 
directions: one branch, as we already mentioned in Vol. XIV, p. 402, to the Sphingidae, another branch to the 
Geratocampidae resp. Brahmaeidae, a third to the Dioptidae, and a fourth to the Drepanidae. The latter branch 
has probably separated a very long time ago, for in the Drepanidae we meet with the majority of those qualities 
we are used to find especially developed in notoriously old families: i. e. a frequently most excellent adaptation 
to dead objects, whereas mimicry or frightening colours do not occur in a single case. 
The larvae still exhibit the exact Notodontid shape and polymorphism: either humps, or horns or 
caudal spikes, sometimes 14 or 16 feet. The imagines are mostly copies of dry leaves, but sometimes also 
excellent imitations of little clods of earth or of birds’ droppings. They are certainly not protected by sharp 
saps, and the few diurnal species flying in the sunshine therefore exhibit the swaying, rocking, doubling flight 
which makes the capture very difficult, as we see it for instance with the males of Aglia, Eudia , Orgyia, Pantana 
etc., but which is generally not met with internally protected lepidoptera, such as the species of Zygaena. —- 
The few American Drepanidae which, as we mentioned, are confined to the nearctic district, are all allied to 
palaearctic species. The statement that the palaearctic Cilix glaucata occurs in America, as for instance 
mentioned in Hampson’s Fauna of India *), is a mistake. 
