184 Miscellaneous. On the Appearance o/Danais Archippus in Auitralia. To the Editors of the Annals and Magazine of Natural Historij. Uiiiversitv of Melbourne, 19th May, 1873. C KNTLEMEK, — Referring; to the notice I sent you last month of the sudden appearance of the American butterfly, Danais Archippus, over a north and south area of ten miles about Melbourne, and my having the year before recognized it as an abundant visitor over the north-east part of the continent of Australia, I beg to say that I have since received specimens in a letter from Mr. Eastwood, showing that it ap-peared in abundance for the first time within the same week at Bel-fast, about two hundred miles west of Melbourne. I have now a letter showing that it appeared about a week later in the north of the island of Tasmania, to the south. I have, &c., Predeeick M'Coy. On the Habits of unequal Bivalve Shells. To the Editors of the Annals and Magazine of Natural History. Burton-on-Trent, .July 3, 1873. Gentlemen, — Dr. Gray asks for information as to the habits of une(]ual bivalve shells. In May last I found many specimens of Pandora incequivalvis, L., in St. Aubin's Bay, Jersey. They were exposed at very low water, and were lying in furrows of sand which were fiUed with water. They lay indifferently on either valve, and were quite destitute of byssus or any marks of attachment. The animals were all alive and apparently healthy. Philip B. Mason, M.R.C.S., F.L.S. On the Skeleton of Kogia Macleayii. By Dr. J. E. Gray, F.R.S. &c. The British Museum has received two skeletons of this interesting whale from Australia, of different ages. The skeletons liave not been mounted yet ; but the larger is about 9 feet long. The larger skull is about IG inches, and the smaller one VSk inches long. The two skulls are very similar ; but the opening between the upper surface of the intermaxillary bones is much wider in one than in the other. The comparison of these two skulls with the very young one figured as Physeter simus by Prof. Owen (Trans. Zool, See. vi. 1. 12, 13, 14), obtained by Mr. Elliot on the coast of India, shows that they are only different ages of the same species. The young one chiefly differs in the sides of the frontal cavity being more convex and swollen, becoming sharper in the older specimens. The vomer is much more exposed below in the two young skulls than in the more adult one, where it becomes partly covered by the under inner edge of the intermaxillaries. The large ridge just over the very large left blower is much higher and more convex in the older specimens than in the middle-aged and young.