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Show 484 MR. P. L. SCLATER ON CERCOPITHECUS GRAYI. [June 19, on to the pupils without it showing any signs of discomfort, nor did the animal trouble to use its nictitating membranes. In this respect it had the advantage over the big Felidae with pupils which contract in a circular manner, since a circular pupil can never contract completely so long as it remains a circle. I obtained precisely the same contraction with a solution of eserine, whilst atropine or cocaine invariabl}'' dilated the pupil to its utmost extent, so that uuder the influence of these two latter alkaloids all pupils became perfectly circular (fig. 2, p. 483). In all Mammalia which I have so far examined I have noticed that when atropine is first dropped into the eye a slight contraction invariably precedes the dilatation. This is most noticeable in the Felidae, as the pupils are so large. In man it may easily be overlooked, owing to the small size of the pupil. Suddenly alarming a cat has the effect of momentarily dilating the pupil; whilst I have noticed that during sleep the pupil is contracted to an oval, but dilates to its normal condition as soon as the animal wakes. In the Wild Cat, the Gleneta, and the Civet I found the pupils to be very large and round, but in bright light they contracted to an oval in the same manner as in the domestic cat. In the Lion, Tiger, Puma, and Leopard, in fact in all the large Felicias, the pupil is invariably round, and as a rule retains its circular shape when contracting, thus forming a decided contrast to the smaller Felidae. June 19, 1894. Dr. A. GTUNTHER, F.B.S., Vice-President, in the Chair. Mr. Sclater laid on the table the skin of a Monkey of the genus Cercopithecus, which had been deposited in the Society's Gardens by Mr. Wall, of 4 Lansdowne Place, Bussed Square, on the 5th of March, 1894, and had died shortly afterwards. He pointed out that this Monkey unquestionably belonged to the local form which he had spoken of in his paper on the Cereopitheci (P. Z. S. 1893, p. 255) as Cercopithecus diana ignitus, and which differed from the ordinary Diana Monkey in its bright chestnut thighs, shorter beard, and other smaller particulars. Mr. Sclater had lately seen a mounted specimen in the Berlin Museum, apparently also referable to this form of C. diana. Mr. Sclater also exhibited the typical specimen of Cercopithecus gragi, Fraser, formerly in the Knowsley Collection, and now belonging to the Free Public and Derby Museum, Liverpool (cf. P. Z. S. 1893, p. 256), which had been kindly sent to him for examination by Mr. Plenry O. Forbes, Director of that Museum. Mr. Sclater pointed out that there could be no doubt that this |