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Show 1882.] ANATOMY OF THE TODIES. 445 The triceps is Y-shaped at its scapular origin, and receives no tendinous slip from the humerus. The construction of the syrinx may be best understood from an inspection of the accompanying figures (p. 444), representing the anterior (A) and posterior (B) views of that of Todus dominicensis. The trachea terminates below in an ossified bony box, formed of three or four modified rings (probably bronchial) fused together, as is very evident in the posterior view : as may also be seen there, the two preceding tracheal rings are coossified with this box in the middle line posteriorly, though in front they are quite free from it. The box is deeply notched in front, a narrow pessular bar running backwards from the apex of the notch, forming a three-way piece. The bronchial semirings succeeding the box have the normal character. The lateral muscle of the trachea continues downwards to terminate just on the upper limits of this syringeal box. The syrinx of Todus viridis is constructed on exactly the same plan. Comparing these figures with those of Momotus lessoni given by Garrod *, it will be seen that Todus differs from Momotus in its syringeal box being deeply notched anteriorly, and much more perfect posteriorly, the two parts being united by a pessular bar unrepresented in Momotus. In fact it resembles that of the Alcedinidae or Galbulidae rather than that of the Momotidae. The chief difference from the former is that in the Alcedinidae the intrinsic muscle, often very broad, passes down over the syringeal box to be inserted on one or more of the movable bronchial semirings, instead of ceasing before doing so, as in Todus. In Galbula there is a bony box nearly similar to that of Todus, but with its sides more strongly concave below, and produced downwards anteriorly into strongly projecting points ; the lateral muscle only passes on to the lower margin of the box, thus stopping short, as in Todus said Momotus, of the movable bronchial semirings. As regards the pterylosis, there is a strange oversight on the part of Nitzsch 2 and Murie 3 as to the condition of the oil-gland, both these observers stating it to be nude. In fact it is, in all the four species of the genus, provided with a very well developed, and even long, tuft of plumes, therein completely differing from that of the M o m o tidae, in which the tuft is either altogether absent or quite rudimentary4. In both T. viridis and T. dominicensis I count twenty remiges, ten being secondaries ; Nitzsch and Murie give nine, having apparently failed to observe the most proximal, smallest one. Nitzsch's figure of the pterylosis in Todus, having nearly certainly been constructed from an examination of the skins only, is not quite accurate- it making the outer pectoral branch to the inferior tract too markedly divergent, and not showing the weaker lines of contour-feathers that run from its apex to the hypopterum. The connexion between the dilated part of the main pectoral tract as it passes on to the breast and the patagial feathering is also made unduly important m his figure, this connexion in reality consisting only of some slight, scattered, i L' 49 8 3 L. c. p. 679. * ' Pterylography,' Bay Soc. ed. p. 88. 4 Cf. Garrod, I. c. p. 427. |
