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Show 474 MR. W. A. FORBES ON LEPTOSOMA DISCOLOR. [Julie 15, a small notch ; behind they are less and less complete as they go downwards. The first semirings are posteriorly closely applied to, though separate from, the pessulus, and are apparently continued on, as cartilaginous rings, posteriorly, so as to form complete or nearly rings. The posterior ends of the second and third semirings where they appear behind are widely separated from their fellows of the other side. The fourth and succeeding bronchial rings are all cartilaginous. Of these the fourth is the largest, being nearly straight, and slightly more prominent than the others. To its middle, rather towards its posterior margin, is attached the (single) intrinsic syringeal muscle. The rings succeeding the fourth ring rapidly become more and more complete, at the same time that the bronchus becomes less capacious, the whole tube tapering away from this ring as it approaches the lung. The fifth and sixth semirings are more slender than those that succeed them, and are slightly concave upwards. The remaining ones are straighter and deeper. Except between the fourth and fifth, and fifth and sixth semirings, the interannular intervals are exceedingly narrow. This syrinx does not show much similarity of form to that of Coracias garrula, the only one of the family of Coraciidae that I have been able to examine as regards this point. At the same time it does not much resemble that of any Cuckoo I a m acquainted with. Reviewing the facts already stated, it is clear that the affinities of Leptosoma to the Cuculidae are very remote, whilst, on the contrary, its relations to the Coraciidae are quite the reverse. The subjoined tabular statement of the principal points in the structure of the three just named groups will perhaps render this additionally clear:- Cuculidas ... Leptosoma... Coraciidae ... CO ~-i <D eg 10 12 12 rfl CD "3 + + fl , c3 .-+3 "3D "5 rH •*-* o - - CO CfD l .3 a + - - fl OoS 1 fCD l fe + + + d 54-1 d •o3 + - - '-0 fl "a CD CC + + + -4-3 a CD CO d o + + + .*-d &.fl x fl fe g CQ peculiar ciconiine ciconiine -43 • rH o triangular oval oval 0* "3 O 2 2 2 cS o O6 + + + In common with both Cuculidae and Coraciidae, Leptosoma possesses a nude oil-gland and long caeca, two carotids, and the femoro-caudal, semitendinosus, and accessory semitendinosus muscles. Wherever there is any difference, Leptosoma resembles the Coraciidae; and the same story is told by the pterylosis and tensor-patagii arrangement. Nevertheless, both in the syrinx and in these last two points, as well as in some others, especially osteological ones1, Leptosoma is not quite typically Coraciine, and it m a y therefore be retained, as 1 Vide Grandidier's work, Atlas, Ois. pis. 85, 86. |