SACRED IBIS. 53 



of the bronchi are very distmct; and I must confess 

 myself at a loss to account for this irregular arrangement. 

 The trachea occupies the anterior surface of the oeso- 

 phagus at the entrance into the thorax. The a-sophagus 

 proceeds to its destination between the bronchi. Probably 

 one reason for the compressed figure of the inferior 

 part of the trachea, may be for the purpose of allowing 

 large erpetalous animals to descend in deglutition with 

 greater facility than could otherwise happen without 

 impediment to respiration ; for in consequence of the 

 ossified structure of this singular portion of the Aspera 

 arteria, neither the pressure of the individual by its 

 volume, nor by its struggles in articulo mortis, would 

 cause obstruction." 



My figure is taken from a female specimen, (which 

 differs only in being rather less than the male,) sent 

 me kindly by IMr. Tristram. It was captured at Chartum, 

 and for aught we know may have been one of Dr. 

 Vierthaler's young birds. It bears the date of July, 

 1852. 



The e^g is from Thienemann. 

 • It has also been figured by Savigny, Egypte, pi. 7. 



