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Show 1905.] OF THE GENUS RHINOLOPHUS, 117 point. The geographical line separating the two branches coincides with the line separating the " Austro-Malayan " from the " Indo-Malayan " subregion (Celebes being a part of the latter). The eastern branch is, as yet, represented by four known species Rh. simplex, megaphyllus, Iruncatus, and nanus. The western by all the others. The further evolution, from borneensis to ferrum-equinum, has been discussed above, and is summed up, in the briefest possible form, in the subjoined diagram (p. 120). But the sketch of this group would be deprived of some of its most instructive features if the Ethiopian species were left quite out of consideration. They belong to three closely related types:- (1) Ethiopian species of the borneensis-stheno-rouxi type.- Far south in Africa, in Bechuanaland and Mashonaland, we find two small species, Rh. clenti and simulator, described quite recently *. They are the Ethiopian representatives of the borneensis type : the same general shape of the skull; essentially the same dentition; the same parallel-margined sella, with a faint or almost imperceptible constriction at the middle; the same style of connecting process; the same proportionate length of the fourth and fifth metacarpals ; even the same length of the tail, &c. But there are, in these species, three characters of especial interest, because they enable us to determine still more precisely their phylogenetic place : the nasal swellings (side view) are more projecting than in borneensis, but less than in stheno; III.2 is lengthened, and IV .1 somewhat shortened, as in this species,- proving that they hare originated from a Bat which had already traversed a part of the distance separating borneensis and stheno. The dentition is on a slightly higher level than in borneensis and stheno, the only difference being that p2, although still in the tooth-row (as in the Oriental species), shows a distinct tendency towards the external side. In the extreme south of Africa (Cape Colony) we find a species,. Rh. capensis, which, quite superficially, looks like an enlarged Rh. simidator. It is an African representative of Rh. rouxi: the skull is to such a degree that of rouxi that it would be hard to find any tangible difference, even the measurements being practically the same (on an average smaller than in rouxi); the nose-leaves (sella, process, lancet) are the same; proportionate length of fourth and fifth metacarpals, of tail and tibia, the same. But the dentition is somewhat more advanced: p2 is generally external, but still, very often, a quite distinct interspace between the canine and p4 indicates its former place; III." is somewhat lengthened. In short: Rh. capensis is a " Rh. rouxi " which in the wing-structure has taken a course towards, in the dentition very slightly beyond, the affinis-stage. (2) Ethiopian species of the affinis -type.-On the coasts of the Bed Sea we find a species, Rh. clivosus, first made known by Cretzschmar from Mohila in Arabia; I have seen examples from * Thomas, Ann. & Mag. Nat. Hist. (7) xiii. (1901) p. 3 86; Andersen, op. cit. (7) xiv. (1904) p. 384. |