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Show 112 PROF. A. H. GARROD ON THE [Feb. 4, facts to add. I may, however, mention that it is only in the Cra-cidee, among allied birds, that the vomer runs so far forward in the palate at the same time that it is tumified at its anterior extremity. In Ortalida albiventris thisris most strikingly the case. The alimentary canal has been so fully described by L'Herminier1, that it is quite unnecessary for m e to enter into detail with reference to it. Johannes Muller2 has noted one or two points concerning the windpipe. Figs. 1 and 2 (pp. 110, 111) represent its anterior and posterior aspects. The lowermost four tracheal rings are consolidated together, and the first pair of bronchial semirings with them, to form a box-like three-way piece, the pessulus posteriorly running up to join the middle of the penultimate ring. The second pair of bronchial semirings does not articulate with the first, they in all respects resembling those nearer the lungs. It is possible that what is above considered to be the first pair of bronchial semirings may be the last tracheal ring. That there is a small notch interrupting the continuity of the inferior mid-anterior margin of the tube formed by the consolidated rings, and that the ring above the lowest segment of the consolidated tube is incomplete behind, are, however, facts in favour of the former view. Among the Gallinae the only genera which at all approach Opisthocomus, as far as the lower larynx is concerned, are those of the Megapodidee. The two carotid arteries of Opisthocomus, where they meet in the front of the neck, become bound together much more intimately than in most birds, although at the part where it is impossible to dissect away the one vessel from the other, a cross section proves that the two tubes are still quite separate. Myologically, the great gluteus (tensor fasciae of m y earlier papers) completely covers the biceps cruris superficially. The fifth gluteus, which runs from the ilium a short distance behind the acetabulum, and covers with its triangular tendon the trochanter of the femur, is present, but small. The semitendinosus and its accessorius are both large, as are the femoro-caudal and its accessorius. The myological formula3, as far as these muscles are concerned, is therefore A B XY. The ambiens muscle is present and small; but its slender tendon, in every case but one of the six knees I have examined, is lost upon the capsule of the front of the knee. In the one instance it traversed the fibrous tissues of the quadratus-tendon, as in other birds whern it is present, to join the digital flexors in the back of the leg. A similar imperfection in the development of the ambiens is sometimes found in Sula bassana, Stringops habroptilus, and in the species of the genus OZdicnemus. The obturator internus is triangular in shape, as in the Gallinae. In the deep tendons of the foot, the flexor hallucis longus sends a 1 Comptes Rendus de l'Acad. des Sciences, 1837, vol. v. p. 435. a Berichte Akad. d. Wissenscbaft. z. Berlin, 1811, p. 177. 3 Vide V. Z.S. 1874, p. 111. |