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Show 1892.] MR. A. THOMSON'S REPORT ON T H E INSECT-HOUSE. 193 experience. I found the structure to be present in Ageronia feronia and arethusa. The other structure to which I wish to draw attention is the distortion of the hind wing found in the males of certain Noctuina of the subfamily Ommatophorince, e. g. Patula macrops and the various species of the genus Argiva, large Moths very common all through the East. In the females of both Patula and Argiva (fig. 4) the neuration is of the ordinary Noctuid character. In the males of Patula (fig. 5) there is a very large glandular fold covered with long, silky, closely matted hairs, and with a tuft of long hairs projecting from it, attached to the costa and folded over on the upper surface of the wing, and one notices that instead of the usual nine emarginations of the outer margin there are only five. But it is not till the wing is denuded of scales that we see the nature of the change that has taken place; when this is done, we see that instead of vein 8 going to the apex of the wing it is vein 4 that does so, that the functional apex is really the middle of the outer margin, and that the whole costal half of the wing has been transformed into the glandular fold, carrying the nervures with it, perhaps for purposes of nutrition. In the males of Argiva (fig. 6) we find that this has gone one step further ; the fold and glandular patch are very small, but it is vein 3 that goes to the apex and there are only four emarginations of the outer margin, the other veins being represented by small aborted detached fragments near the base. The glandular fold is almost certainly a scent-organ, and I suggest that Argiva once possessed an even larger one than Patula, and that this fold, becoming detrimental or useless to it, either from hindering flight or some other cause, has been aborted, carrying the neuration with it. March 15, 1892. Prof. Flower, C.B., LL.D., F.R.S., President, in the Chair. Mr. Arthur Thomson, the Society's Head Keeper, exhibited a series of Insects reared in the Insect-house in the Society's Gardens during the past year, and read the following Report on the subject:- Report on the Insect-house for 1891. Examples of the following species of Insects have been exhibited in the Insect-house during the past season :- Silk-producing Bombyces and their Allies. Indian. Attacus atlas. Anthercea mylitta. cynthia. Actios selene. pernyi. Cricula trifenestra. |