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Show 324 ON THE TRACHEA AND SYRINX IN CERTAIN BIRDS. [J part of the trachea, while the presence of a membranous wall completing internally the upper bronchial half-rings recalls the Ardeine syrinx. Mycteria americana has a syrinx which is again intermediate between that of Xenorhynchus and the typical Storks; the bronchial Fig. 3. Syrinx of Xenorhynchus scncgalcnsis. rings are complete internally as in the latter, but the rings, instead of being of uniform width, are considerably narrower on the inner side of the bronchus, which therefore becomes largely membranous. Abdimia sphenorhyncha (fig. 2) is another Stork which presents even a closer resemblance to the Herons in the form of its syrinx ; the membranous inner wall of the bronchi is more largely developed than in Xenorhynchus, indeed quite as much as in the Ardeidec; but there |