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Show 408 MR. G. E. DOBSON ON THE ERINACEID.E. [Mar. I, upwards and to the left side; and in the liver (fig. 5), which has much shorter and thicker caudate lobe (as indeed might be expected in a comparatively much shorter animal). But very considerable variability in the forms of both these organs is observable in the different species, no two species agreeing closely. The intestinal canal, however, in length and in its general construction is very similar throughout the whole family. The lungs are constructed very much on the same plan as in Gymnura ; but they are comparatively smaller, as might be expected in animals depending on their armour, and not on their speed, in making their escape when attacked by enemies. The right lung is divided more or less completely into three lobes; but the left is quite undivided ; the azygos lobe is well developed and pyramidal in outline, the apex of the pyramid, not the base, as in Gymnura, being at its lower extremity (fig. 7, p. 400). The uterus (fig. 9, p. 401) scarcely differs in form throughout the species. It exibits an advance in development; for, although the cornua are even longer than in Gymnura, there is a true corpus uteri, into which they open at right angles. The os uteri is not enclosed in a hood, as in G. raffiesii; but one or two deep folds occupy the uterine extremity of the vagina, which are so large that, as John Hunter remarked, they appear at first as if they were the os uteril. A review of the anatomy of the species of Erinaceus not only adds valuable aid in attempting their systematic arrangement, but also, when we compare it with that of Gymnura, leads to the conclusion that they are but differentiated forms of some animal of which we have very probably a close representative in G. raffiesii, which we may expect will be hereafter proved to be a very ancient form, perhaps one of the sole survivors of a once widely extended group of predaceous Insectivora. EXPLANATION OF THE WOODCUTS. Fig. 1. Crown of first upper molar, right side, of Gymnura raffiesii, showing the fifth central cusp, which is connected by a ^-shaped ridge with the bases of the two internal cusps. 2, 3. Stomach of Gymnura raffiesii and of Erinaceus europceus (reduced). 4, 5. Posterior surfaces of livers of the same species (much reduced). 6, 7. Lungs of the same species, from below, half natural size. 8, 9, Uteri and vagina? of the same species. The uterus of each is shown in section; the vaginal walls are divided and reflected. The different positions of the urethral aperture (ur) in the two species is noticeable, and the presence in G. raffiesii of a hood concealing the os uteri (o «). 10, 11. Anterior halves of the skulls of Erinaceus europceus and E. blanfordi (enlarged). Figures 1, 10, 11 are from enlarged drawings by Mr. Mintern, from specimens in the collections of the British Museum and of Mr. W . T. Blanford, F.E.S.; figures 2-9 have been reduced by Mr. Smit from drawings by the author. 1 As no specimen of a male Gymnura has yet been obtained for examination, the male organs of Erinaceus are not referred to here ; they will be found fully described in the work referred to on p. 389, as well as all other parts which have been but cursorily touched upon or are not described in this abstract. |