THYRIDIDAE. General Topics. By Dr. A. Seltz. 
1187 
Family: Thyrididae. 
Since the beginning of the present century our knowledge of the forms belonging to this strange family 
has increased enormously, yet we know very little to this day about the habits and the systematic connections 
of the different genera. The biology is known only of the sole genus occurring in Europe, while all the exotic 
species are known merely in their imago stage. 
In dealing with the latter in Vol. X, p. 743, we had pointed out that there is an extraordinary variety 
in the habitus of this one, not very large family (Wagner's Catalogue [by Dalla Torre] enumerated about 
500 species in 1914). A number of the species resemble the Pyralidae not only in their shape but also in their attitude, 
in flying, in selecting their resting places, in their behaviour on being captured by the lantern etc., and besides 
they also show similar peculiarities in their anatomy. Others again are of a heavy, unwieldy build, assuming 
a beetle-like flight so that they might rather be taken for wood-bugs ( Pentatomidae or Scutelleridae). In some 
(Hepialopsis spkingipennis, Zeuzerodes fasciata) we even find a Sphingid shape, then again the habitus of 
Syntomidae (Diphya [Gippius] sumptuosus, Glanycus etc.), the shape of Noctuae similar to the Eutelia (such 
as Dysodia), such of a Geometrid exterior as for instance Rhodogonia miniata and Macrogonia. Besides there 
are quite a number of species exhibiting most strangely shaped wings and bodies that are unparalleled in the 
whole lepidopteral kingdom, for instance Zeuzerodes fumatilis , Draconia denticulata, some Risama etc. Moreover, 
there is often a strange harmony in the outward appearance of some species the habitats of which are some¬ 
times situated in quite a different part of the world, and which exhibit also an entirely different anatomy. 
This i$ not so very astonishing in those cases where such species belong to the same genera distributed over 
several continents, yet it is rather difficult to believe in a very close interior affinity between Rhodoneura 
triumphans from Ecuador and the quite similarly marked Rhodoneura pudicula from the Moluccas. But it is 
rather strange to see how the very same, sometimes quite abnormal coloristic designs are repeated in altogether 
different genera living in quite different continents. A man meeting a Morova subfasciata in New Zealand may 
imagine to be transferred to Pennsylvania, where he started the common Iiexeris enhydris from the bushes, 
showing the very same shape, colour and marking of the wings. Yet it is n o t astonishing if adaptations to 
the same objects lead to the same transformations and developments in different animal groups. Thus Risama 
falcata seems to be adapted to the same shape of a leaf as many Geometrids of the genus Oxydia are, and since, 
according to the well known theorem, two objects resembling a third must also be similar one to the other, 
it would be entirely wrong to presume mimicry in such cases or to regard their geographical separation as a 
criterion opposed to this theory. 
The family has undoubtedly nothing whatever to do with mimicry. On the contrary, as we have just 
mentioned, it abounds extraordinarily in quite uncommon shapes of the wings and no less in the designs of 
colouring. We do not exaggerate if we say that the design of Herdonia, for instance Herdonia miranda, is un¬ 
known in the whole other insect kingdom. Risama pi eta and Draconia peripheta are in America just as un¬ 
mistakable lepidopteral forms as Camptochilus sinuosus in India and Psycharium pellucens or guttulosa among 
the African Thyrididae. 
Several monographies and catalogues have already been published on the Thyrididae, thus in 1892 
a monography on the “ Siculidae” (a name for the group more commonly used by older authors such as Le- 
derer, Gitenee) by Pagenstecher; besides a Catalogue by Hampson in 1897, and Pars 20 of the Lepidopter- 
orum Catalogus by Dalla Torre in 1914. The figures, however, which were at disposal till the corresponding 
volumes of the “Macrolepidoptera” appeared, were extremely scanty; on the one hand because only 1 or 2 
specimens have become known of a relatively great number of species, mostly by reason of their being very 
rare or living in excellent hiding places; on the other hand, many species were represented by badly preserved 
specimens which made it impossible to supply a precise figure. The privilege of being able to publish for the 
first time such a vast number of figures (altogether more than 340 figures of Thyrididae and 150 for the American 
