The Wing and Larval Characters of the Emperor 
Moths. 
By A. RapcuirFE Grote, A.M. Read January 13th, 1808. 
A CONTROVERSY has arisen with regard to the classification of the 
emperor moths, which is of special interest in so far as one of the - 
species, Saturnia pavonia-minor, 1s British, while the question in its 
larger aspects has so profound a bearing upon the value of taxonomic 
character in the Lepidoptera that this must be my apology for bring- 
ing it before the Society. 
At the outset it is necessary to free the controversy from all irre- 
levant and side issues, and to state the matter plainly. Are we to 
classify the common Continental tau emperor moth, Ag@a fan, 
according to the wing characters, which is my contention, or are we 
to ignore these, and give weight to the fact that the larva bears a 
single dorsal tubercle on the ninth abdominal segment, which is 
Dr. Dyar’s opinion ? 
Incidental to the publication of Dr. Dyar’s classification, and in 
the progress of the controversy, I have been accused of not fully 
appreciating the neurational characters of Agfa. It is Dr. Dyar’s 
opinion that this does not necessarily contradict that of Saturnza. 
Upon this point I must be here quite clear. I must sustain my 
original position, and I must also show that Dr. Dyar’s attempt to 
reconcile the wing characters of Ag/a with his classificatory scheme 
based on the larval tubercle, is due to his want of familiarity with 
what are probable or even possible modifications of the courses of 
the veins of the wing upon one and the same phylogenetic line. 
The controversy is made doubly sharp by the fact that it includes 
the position of the American genus Hemz/euca, which, from analogous 
reasons, I refer to the Saturnians, and Dr. Dyar, on the contrary, 
as belonging to the same family with Awfomeris. (Questions of classi 
fication become cosmopolitan, for the reason that they cannot be 
answered from the study of the fauna of a single country. In this 
case, owing to the extent of the British Empire, all the American 
genera in question inhabit Her Majesty’s dominions. 
The wing of Ag/ia is very nearly the exact copy of the wing of the 
American genus Automeris, with which I would associate it. It has 
every main feature of its distinctive pattern. It merely differs from 
Automerts by being slightly more specialised. The slight changes 
are parallel to those explained elsewhere by me in discussing the 
different actions accompanying the suppression of the median system 
of veins. Vein VIII of the hind-wings has become lost or absorbed 
