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Show 610 MR. W. A. FORBES ON THE UAKARI MONKEYS. [Nov. 30, and not at all in the remaining three. In the same collection, a single skull of an Ateles (4717a) also shows no trace of this union. In all the remaining genera, so far as I have yet seen, the rule holds good. I was first struck with the arrangement here described when examining the collection of Monkeys' skulls in the Cambridge Museum ; and finding that there was no exception whatever, either there or in the skulls belonging to the Prosector's department, I examined the entire collection of unmounted skulls in the College-of-Surgeons Museum (including nearly every known genus of Monkey), with the results already mentioned. The character is at all events worth knowing for practical purposes, even if of no greater scientific value. This, of course, must be left open for more extensive examination1. The brain of Brachyurus rubicundus is represented in the accompanying figures (figs. 7-10, pp. 642, 643), which give views of its superior,inferior, external, and internal aspects, of the natural size, drawn after the organ had been hardened in spirit for a short time. The total length of the hemispheres is 2*3 inches, their greatest breadth 1*8 inch, whilst the vertical depth is about 1*25 inch. Viewed from above, the hemispheres have a fairly rounded contour, and the cerebellum does not project beyond their posterior margin, though it appears above in the middle line between the somewhat cut-away inner margins of the occipital lobe. From the side, the hemispheres are seen to be but slightly arched. The occipital lobe is well developed, and the orbital surfaces but little excavated. The temporal lobes are also well developed. The hemispheres possess the most important sulci characterizing the Simian brain well developed ; as regards their complexity, they stand between Ateles, Cebus, and Lagothrix, on the one side, and Callithrix, Mycetes, Pithecia, &c, on the other. The Sylvian fissure2 (s.) is well developed, running upwards and backwards to end, *3 inch from the middle line of the hemispheres, a little in advance of the spot where the temporo-occipital sulcus 1 P.S. Jan. 27, 1881.-My views have been both confirmed and anticipated by Dr. Gustav Joseph, in a paper in the first volume of the ' Morphologisches Jahrbuch' (i. pp. 453-05, Taf. xv.). Whilst m y paper was going through the press, Prof. Flower was kind enough to call my attention to this paper, as well as to another by the same author in the ' Bericht der Schlesischen Gesell-schaft '-which, as yet, I have not been able to see-both being referred to in a recently published ethnological paper (in Eussian) by Demetrius Arnoutchine, which also, apparently, contains some more information on the same subject. - In the following description of the sulci, &c, I have in the main followed the nomenclature proposed by Prof. Huxley in his valuable paper on the brain of Atelespaniscus (P. Z. S. 1861, pp. 247-200, pl. xxix.), and adopted by Prof. Flower m his descriptions of the brains of Mycetes scniculus (P. Z. S. 1864 pp. 335-338, pl. xxix.) and Pithecia monachus (P. Z. S. 1862, pp. 328-331). The late Dr. Paul Broca has more recently written an elaborate article on the subject of cerebral nomenclature ("Nomenclature Cerebrale, denomination des divisions et subdivisions des hemispheres et des anfractuosites cle leur surface " Eevue d'Anthropologie, (2) i. 1878, pp. 193-236). In this he endeavours to hunt more strictly than has hitherto been done the terms used by various writers or, the structure of the brain, and to introduce a uniform nomenclature 1 have, where necessary, added his names in brackets after those here used |