22 
PAPERS READ BEFORE THE SOCIETY. 
THE RHEUMAPTERA HASTATA GROUP. 
(Read December 19th, 1905, by LOUIS B. PROUT, F.E.S.) 
The subject of my paper this evening was suggested principally by 
material in my own collection, and the drawer of black and white 
Geometrides which I have passed round for exhibition may serve in 
part as a basis for my remarks. The fact that I am rather well pro¬ 
vided with the principal forms of hastata and its closest allies, and have 
also types of some Eastern species bearing more or less affinity thereto, 
and the further fact that my kind friend Dr. Chapman, in presenting 
me with some specimens of liictuata Schiff. ( liujubrata Stgr.), spoke of it 
as a close ally of hastata, these were among the principal causes of my r 
overhauling this section of my collection and preparing the following 
notes. 
I believe all the species contained in my drawer have some consider¬ 
able natural affinity, but it will be manifest to you at a glance that 
they do not form one genus, and that they could hardly all be described 
as forming the “hastata group.” The first group, the comparatively 
narrow-winged black species with narrow or broad white central bands, 
comprises the genera Baptria (tibiale Esp., with vars.), Trieliodezia 
(haberhaueri Led. and exsecuta Eeld.) and Neodezia Warr., recently 
erected (Nov. Zool., xi., p. 541) for the American representatives of the 
last-named ( albovittata Guen., etc.) which have not well developed the 
hair-tuft to which Trieliodezia owed its name. There are some 
interesting structural questions in connection with the group, but I 
am not going to discuss them on this occasion. N. albovittata (in¬ 
congruously placed by Hulst in Euchoeca) is, as I am informed by Mr. 
R. F. Pearsall, of Brooklyn, a day-fiier, like so many black or black- 
and-white species, and I suspect the same is true of Baptria and 
Trieliodezia. In fact most, if not all, of the black-and-whites which I 
am exhibiting will come under the same category, and this will account 
in part for their similarity in coloration. For instance, the next species 
to which I would direct your attention, semenovi Alpb., is superficially 
very like higens Oberth., but as it differs not only in its pectinated 
antennas, but also in neuration, and probably some other characters, 
it is referable, in the present state of our knowledge, to the genus 
Xanthorlioe, or at any rate not to Rheumaptera. 
Tristata and its group, again, placed near hastata ever since the 
time of Linnaeus, are in like case. Not only the imaginal structure, 
but here also the weighty support obtained from larval characters*, 
suffice to place this group with alternata Mull, (sociata Borkh.), etc., in 
* Aurivillius Nord. Fjar., p. 236) apparently ignores these latter, for he 
mentions the close relationship of “ Cidaria" hastata and tristata as an argument 
against using the formation of the discocellulars for generic subdivisions of that 
unwieldy “ genus.” 
