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Show 1891.] MR. F. E. BEDDARD ON HAPALEMUR GRISEUS. 457 two Lemurs themselves are of about the same size ; but it is interesting to note that the brain of Hapalemur is distinctly larger in total size. I cannot compare it with the brain of Lemur anjuanensis, as I did not preserve any record of the measurements of that individual. As there is no description, so far at least as I am aware, of the brain of Hapalemur, I have considered it worth to give the following-description illustrated by the drawings which I exhibit (fig. 4 A and B). The brain of Hapalemur is of an oval form: it is not sharply compressed anteriorly, as is the brain of Lemur; neither do the hemispheres diverge from each other so markedly behind as in that Brain of Hapalemur griseus. A, from above ; B, lateral view ; S (in both figures), Sylvian fissure.' genus and Galago. The convolutions, however, show only slight differences from those of Lemur. In Professor Flower's figure of the brain of Lemur nigrifrons1 the angular sulcus is quite distinct from the infero-frontal, and I find that this is also the case with Lemur anjuanensis. In Hapalemur griseus these two furrows are present, as shown in the accompanying drawing, and have precisely the same shape as in Lemur; but there is hardly a break between the anterior end of the angular sulcus and the posterior end of the infero-frontal ; they form practically a continuous sulcus. The Sylvian fissure in Hapalemur extends rather further back than in Lemur, running for a short distance parallel with the angular fissure : with the exception of these small differences, the brains of Hapalemur and Lemur appear to m e to be very similar. Prof. Milne-Edwards has deVoted two plates of the magnificent ' Histoire de Madagascar' 'A to the illustration of the brains of the Indrisinse; those of the genera Propithecus, Lndris, and Avahi are figured in many aspects. It is quite clear from these admirable figures that while there are not wide differences between the Indrisinse and other Lemurs, the brain-configuration of the former shows no 1 "On the Brain of the Javan Loris (Stenops javanicus, Illig.)," Tr. Z. S. vol. v. p. 103. 2 ' Histoire Naturelle etc. de Madagascar,' Mammit'eres, Atlas, pis. 86, 87. |