496 ON THE TRACHEA OF THE GALLINA. 
the end being slightly less than that next lower down. This fifth 
ring first gives indications of a latero-posterior deepening, with a cor- 
responding reduction of the interannular interval and the formation 
of an antero-median horizontal fusiform space, the only remains of the 
interannular interval recognizable higher up, and extending into the 
cervical portion of the windpipe. 
Ceriornis temmincki differs from all other Gallinze examined by me, 
except Francolinus vulgaris, in that the third bronchial semiring articu- 
lates with the second, and so participates in the formation of the 
specialized organ under consideration. None of the tracheal rings are 
narrowed ; and there are consequently no interannular intervals of any 
kind, if we except the one on each side of a narrow anterior isthmus 
which runs between the penultimate and the last ring. This interval 
is guttate in shape, on account of the slight upturning of the lateral 
element of the last ring, the antero-median part of which is expanded, 
almost exactly as in Euplocamus, into a quadrate cartilage. The pes- 
sulus at its posterior extremity is unattached, though situated as 
usual. Its freedom depends upon the fact that the penultimate as 
well as the last tracheal ring is incomplete behind, the end of the 
pessulus filling the deficiency and just touching the lower margin of 
the complete antepenultimate ring. This may possibly be the normal 
arrangement, all others resulting from subsequent consolidation. The 
first and second bronchial semirings are very much alike. The rela- 
tions of the upper of them to the ring above, as well as those of the 
lower to the ring below, are almost identically those of Huplocamus ; 
whilst posteriorly they consolidate together for one half their length, 
a small elongate fusiform interval existing external to their anterior 
fused extremities. With the lower of them the slightly-bowed third 
Fig. 24. Fig. 25. 
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Front view. Back view. 
Ceriornis temmincki, 
