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Show 1885.] MR. F. E. BEDDARD ON THE CUCKOOS. 171 present the appearance of being wider on one side than on the other ; the first four bronchial semirings increase in length and in breadth progressively ; they are ossified and firmly united together ; to the last of these the single syringeal muscle of either side is attached ; there is a well-developed bony pessulus which does not fuse with the last tracheal ring anteriorly, out is inserted between its slightly divaricated extremities; the remaining bronchial semirings are cartilaginous. Piaya cayana.-The syrinx of this Cuckoo is tracheo-bronchial ; the last ring of the trachea (see fig. 1) is considerably more slender than the rest ; the two first bronchial semirings are of about the same diameter; the third bronchial semiring is of, compara- Fig. 1. Syrinx of Piaya cayana. tively speaking, enormous size, and to it are attached the intrinsic muscles of the syrinx, one on either side ; the following ring is much narrower, but about the same lateral diameter; the rest rapidly diminish in size. The syrinx of Saurothera dominicensis resembles in almost every particular that of Piaya cayana ; the only difference worth remarking upon is that the third bronchial semiring, to which the intrinsic muscles of the syrinx are attached, is not so markedly larger than the other rings of the bronchi. Diplopterus navius, again, shows no great differences in the structure of its syrinx from Piaya and Saurothera; it more particularly resembles the latter in the comparatively small size of the third bronchial semiring. |