120 MR. A. G. BUTLER ON [Feb. ] 6, In the brain the chief differences from T. niger were : the greater depth in proportion to the length ; the Sylvian fissure was much more upright than in the common Chimpanzee, and therefore approached the Gorilla and the other Anthropoids ; the common Chimpanzee came nearest to man in the direction of this fissure. The middle lobe of the cerebellum was overlapped posteriorlj^, and nearly concealed, by the two lateral lobes. The Orang " George" was believed on its arrival to be an adult example of the Lesser Orang, Simla morio, originally described by Sir R. Owen. It proved to be a much younger specimen than had been supposed. AH the milk-teeth were present ; and, although they were unusually worn, none had been replaced by the permanent teeth. The shape of the head was, however, rather different from that of the typical Simla satyrus, being distinctly longer and not so markedly brachycephalic. The external characters, particularly the hands and feet, were described and illustrated, and a full account was given of the muscular anatomy of the limbs. This paper will be published entire in the Society's • Transactions.' The following papers were read : — 1. On a Collection of Lepidoptera from Sandakan^ N.E. Borneo. By Arthur G. Butler^ F.L.S., F.Z.S., &c. [Received January 8, 1892.] (Plate VI.) The Lepidoptera here enumerated were obtained by Mr. W. B. Pryer and presented by him to the National Collection ; many of them have suffered considerably from damp, but, fortunately, the examples of the finest of the new species are in excellent condition. RHOPALOCERA. This part of the collection is of little value, and the specimens are much damaged ; it, however, contains examples of an interesting Elymnias. The following is a list of the species : — Calliploea nia-zares, Moore, Salpinx kadu, Eschscholtz, Elymnias (probably the male of E.penanga, Westw., black above, with the interno-basal lialf and a belt across the apical area of the primaries slaty lilaciue), Eurytela castelnaui $ , Felder, Neptis thamala, Moore, Rahlnda saiidaka, n. sp.', Athyma nefte. Cram., Euthalia dunya. Hew., Lebadea padaka, Moore, Jmathusla phldippus, Linn., Hypolimnas ^ Exactly like R. peraka, excepting that the submarginal band of the primaries is single instead of treble— a distinction which is believed to be constant.