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Show 126 MR. A. G. BUTLER O N THE GENUS TERACOLUS. [Jan. 18, 8. Revision of the Lepidopterous Genus Teracolus, with Descriptions of the new Species. By A R T H U R GARDINER BUTLER, F.L.S., F.Z.S. [Received December 8, 1875.] (Plates VI. & VII.) The Butterflies treated of in the present paper, although admitted by all to be very pretty, are by no means favourite objects of study with the lepidopterist. Whenever a genus is composed of striking and, at the same time, sharply defined species, plenty of entomologists are always ready to work at it; but when, as in the present instance, there is some difficulty in ascertaining the amount of variation obtaining in the different species, it will be found that lepidopterists are not unfrequently content to catalogue all doubtful forms as varieties of known species, often giving to the world a false view of their geographical distribution, and thus hindering instead of advancing science. The genus Teracolus was first founded by Swainson, in his * Zoological Illustrations,' for the reception of his T. subfasciatus. But a few years since I extended it for the reception of all the insects formerly constituting the genera ldmais and Callosune, there being no reason, but that afforded by colour, why they should ever have been kept separate. Until quite recently I was unable, from lack of adequate material, to attempt a revision of this very difficult group ; but the kindness of Mr. E. C. Buxton, in presenting to the Musenm his valuable collection of African " Orange-tips," has at length put me into a fair position to work out the whole of the African species. In order to make the present paper more complete, Mr. F. Moore has very generously lent me the whole of his Indian specimens, thus enabling me to avoid errors in determining the Asiatic species-our deficiencies in Syrian forms being also partially met by the assistance of m y friend R. Meldola, who has put into m y hands several species collected by the late Mr. J. K. Lord. It would be easy to show that the present genus contains but few, if any, very sharply defined species. It is not improbable that, when we know the Butterflies of East Africa, Arabia, Syria, and Persia more thoroughly, we shall be able to show an unbroken gradation from one end of the group to the other. At present we get a nearly perfect transitional series from T. subfasciatus to T. ione, thence through T. halimede to T.fausta, Calais, and allies, on the one hand, and to T. eupompe and allies on the other; from the latter we can run on, almost without a break, through T. eucharis to T. interrupts, and thence to T. evippe. If the plan of " lumping " species were to be adopted in this genus, every year would probably decrease instead of adding to their num- |