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Show 1886.] MR. H. J. ELWES ON THE GENUS PARNASSIUS. 45 As far as I have personally observed, it is found in meadows where vegetation is rather rank ; and at Berisal, on the Simplon pass, where it is most abundant at 4500 feet, the meadows where it flies have a north aspect, while P. apollo confines itself to the hot slopes on the other side of the ravine. With regard to its life-history little is known. Meyer-Diir says that Kindermann discovered the apollo-like larva in April and beginning of May on Corydalis halleri, and that it pupates under fallen leaves in a strong web, the pupa being yellowish and like that of the Zygaenidae. I have made several endeavours to discover the larva myself without success, but I have strong doubts that Corydalis is the only, if even it is the usual food-plant, for this reason, that it is a spring flowering plant of very short duration ; whilst P. mnemosyne must be an autumn-feeding larva, as the insect flies in spring or early summer very soon after the melting of the snow, and there could be no time for the larvae to feed up after it melted. From observations made in Wallis, in June 1884, and again in May 1885, I believe that the larva more probably feeds on an umbelliferous plant (? Heracleum, sp.), which was very abundant in the places where the insect was numerous, and on which the females often sat, whilst Corydalis was either absent or withered at the same date. Herr Bang-Haas thinks that in Denmark the larva is a night-feeder, but knows nothing certainly about it. I was very anxious to investigate the development of the pouch in this species as well as in P. apollo, and with this object visited Wallis in M a y 1885. On May 24, 1 found the males abundant at about 3000 feet on the south side of the valley, near Brieg, and caught several males and fresh females, all of which had the pouch perfect. In the previous year I found, a month later, at Berisal, that the males were worn, and the females, though they were in two or three cases taken in copula, had apparently been flying for some time, and had a perfect pouch. After a good deal of searching I found a female fresh from the pupa, at about 11 A.M., sitting on an umbelliferous plant, either AZthusa or Heracleum. I took her home and put her in a birdcage covered with gauze at about 2 P.M., and at 2.30 one of the males which had been fluttering round her for some time commenced copulation. The female held on to a grass stem with the head upwards and the male hung to her with head down. At 2.45 the female crawled up to the top of the cage, carrying the male with her; he made no attempts to use his feet or hold on, and was supported entirely by the abdomen. At intervals of a few minutes there were slight movements of the abdomen of the male, but otherwise he remained quite torpid till about 4 P.M., when the pair suddenly separated without any appearance of a pouch on the female, whose abdomen remained large and swollen as at first. At 6 P.M. there was not the least change in her appearance ; she remained quietly holding on to the gauze, whilst the male crawled about the cage. In the evening I put another fresh caught male in, and on the following morning put the cage in the hot sunshine at 7.30 A.M. All three insects fluttered and crawled about the cage for some time, but showed no |