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Show 1895.] BEAIN IN THE LEMUES. 147 with the anterior of the two presylvian sulci found in many Lemurs. A very curious thing about the brain of Galago is the very faintly marked antero-temporal furrow. This is so characteristic a fissure of the Lemurine brain, and is the only fissure besides the Sylvian which is found in the otherwise smooth brain of Tarsius according to Burmeister's figures. W e shall see, however, that it is also absent in Cheirogaleus. The parietooccipital fissure is represented by two small grooves starting from the middle line. The brain of 67. monteiri is not very different, but the dent lying in front of the angular sulcus is absent. § The Brain of Cheirogaleus coquereli. (Fig. 5.) This brain, as already mentioned, has a rounded form comparable to that of Loris gracilis, but it is much flatter, iu fact markedly flat. O n the upper surface, behind the Sylvian fissure, is a curious hollowing of the brain-surface, which is unlike anything that I have seen in any other Lemur. The cerebral hemispheres diverge from each other very slightly behind, the posterior margin of the hemispheres being almost straight. Fig. 5. Brain of Cheirogaleus coquereli. Lettering as in fig. 1. The brain is very slightly furrowed, not nearly so much even as in Loris gracilis, which is, moreover, a smaller brain. The only sulcus which is really conspicuous is the Sylvian. There is, as already mentioned, practically no trace of the antero-temporal. The angular fissures are, however, feebly represented by two short, shallow sulci, not more than gth of an inch in length. They are just in the middle of the brain. § Mutual Affinities of the Genera o/Lemuroidea as indicated by Brain-structure. There is no doubt that the structure of the brain of the Aye-aye, as figured by Owen, justifies the placing of that genus in a |