OCR Text |
Show 1899.] INTERNAL ANATOMY OF NOTORNIS. 95 to be independent of any ring, and present a concavity on their outer faces. It is, however, possible that when ossification is complete these two bones will ankylose with the ends of the ring 6. Fig. 5. The syrinx of Notornis, ventral view (slightly more enlarged than fig. 4). Letters as in fig. 4. The remaining syringeal rings (e, f, g) call for little remark. They are all closely apposed, and ventraily curve very sharply round the bronchus to reach the membrana tympaniformis interna, while dorsally the incurved region is very slight. The ring g, owing to its curvature, is much arched forwards at the side, so that between it and the first unmodified bronchial (I) there is a considerable space, across which is stretched the membrana tympaniformis externa. This ring (I) is almost straight, while II is concave upwards; betAveen them is also the thin membrane: another part of it lies betAveen II and III, but this space is much narrower than either of the preceding. On the dorsal side between the ends of each of the rings II/III and III/IV is a small ossicle (s). Passing from the syrinx itself, I Avould refer to a slip of muscle |