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Show 456 PROF. A. H. GARROD ON GELADA RUEPPELLI. [May 20, In Gelada the right and left central lobes are proportionally larger than in the genera above described. Otherwise it most resembles Cercopithecus, differing from it in that the cystic fissure is shallow, at the same time that the fundus of the gall-bladder does not so nearly approach the inferior border of tbe right central lobe. It resembles Cercopithecus in that the Spigelian lobe is absent, at the same time that tbe caudate lobe is long, in both which respects it contrasts strongly with Cynocephalus. The only lobelet is one on the right border of the umbilical fissure, which is Macaque-like. It differs from 3Iacacus in the obliquity of the inferior border of the right central lobe, and in the nearness of the gall-bladder to the umbilical fissure, as well as in the absence of a Spigelian lobe and the large size of the central lobes. The brain of Gelada rueppelli is particularly instructive when compared with the beautiful series of figures in Gratiolet's ' Memo-ire sur les Plis Cerebraux de l'Homme et des Primates.' Its different aspects are represented, natural size, on Plate XXXVIII. Its most marked feature is the relatively small size of the occipital lobe, which is about as large as in the Semnopitheci, smaller than in the Cynoce-phali, and much smaller than in 31acacus as well as Cercopithecus. In the two last-named genera this lobe is unconvoluted, or very slightly so. In Gelada there is a simple horizontal sulcus (h, h) a short distance above its lower border, running from the posterior surface some way forward, but not so far as to meet the posterior transverse sulcus (c, c). In Cynocephalus the occipital lobe is more elaborately convoluted. An inferior horizontal occipital sulcus, parallel to that just described, runs so far forward as to join the major oblique temporoparietal sulcus (b, b). This is a condition recorded by Gratiolet in Semnopithecus maurus only, the sulcus generally turning upwards to end independently. The major oblique temporo-parietal sulcus (b, b) commences below, near the inferior rounded margin of the temporal lobe, and runs upwards as well as backwards to near the middle line of the brain. It is joined by the prolongation upwards of the Sylvian fissure (a, a), two thirds from its lower end, it being bent slightly forward at tbe point of junction. Surrounding the upper end of this last sulcus, but not meeting it, is one whose posterior limb (e, c) forms tbe anterior boundary of the occipital lobe, the posterior transverse fissure, whilst its anterior limb (g, g) runs forwards, downwards, and outwards, to end independently as in allied Primates. Where these two limbs meet a small sulcus runs inwards to the middle line, becoming conspicuous on the median aspect of the hemisphere. The prolongation upwards and backwards of the Sylvian fissure on the outer surface of the brain meets the major oblique temporoparietal sulcus as above mentioned. Whether or not it should meet it is uncertain in allied species of the same genus according to Gratiolet. It is peculiar, however, in that from a little above and below its middle it sends forward small branches (e, e and n, n). In |