Abstract
Here is written a note on Mods ancilla (WARREN), whose occurence in Japan has not been confirmed. I could fortunately obtain a unique male (Kobe, 9 May 1954, SUGI leg.) that has strikingly dissimilar genitalia to those of annetta and it was naturally identified with ancilla through the published description. It is a little smaller than the same brood of annetta, deeper purplish brown, the postmedian line more even and not sharply angled at vein 2, but the hindwing is rather less yellowish compared with the spring brood of annatta, which has markedly yellow terminal area. The male genitalia of the both species are shown. Ancilla may be found mainly in the western part of Japan, and seems to disappear in Tokyo and its neighboring area.
