374 



PROF. A. H. GARROD ON THE 



[Apr. !, 



but anteriorly they are thinner, leaving considerable intervals, dimi- 

 nishing as they ascend — continuous between tbe five rings above the 

 penultimate, found also between it and tbe last, but in tbat case 

 interrupted by a small median connecting isthmus, which is broader 

 below than above, at the same time that it is continuous with the supe- 

 riorly broader medio-anterior descending process of the last ring, 

 the two together forming a lozenge-shaped cartilage that receives 

 the extremities of the first semirings at its lower margin. Posteriorly 

 the pessulus is continuous with the penultimate ring, whilst the ends 

 of the last tracheal also blend with it slightly. The second bron- 

 chial semiring is slightly larger than the first, and articulates with 

 it in the usual way, as does the first with the last tracheal ring. 

 There is a great uniformity in the depths of all the interannular in- 

 tervals in the region of the bifurcation of the trachea. 



Fig. 26. 



Fig. 27. 



Front view. 



Crossoplilon mantcfatricvm. 



Back riew. 



In Numida cristata, which may be taken as the type of the very 

 characteristic windpipe of the genus, figured accurately as it is in 

 part by Temminck ', the peculiarity is that the lowermost six or so 

 tracheal rings develop antero-lateral fenestra between them, in- 

 creasing in size from above downwards, and produced by the thinning 



1 Loc. cit. pi. i. fig. 4. 



