1883.] 



ANATOMY OF PHCENICOPTERUS. 



639 



fused together, and calcified, tlie fourth being incomplete behind. 

 Above these are eight or nine rings, which are also incomplete poste- 

 riorly ; so that above the syrinx there is at the back of the trachea 

 an elongated membranous space. 



Below the last tracheal ring there is a membranous tube, connecting 

 the last tracheal with the first bronchial rings. Of these the first 

 is incomplete internally, both in front and behind ; while the next 

 three are thickened, and join a large pessulus in the middle line. 



Both the pessulus and the first four bronchial rings are complete. 



In Phoenicopterus the last three bronchial rings are calcified and 



Fig. 1. 



Diagrams of the syrinx of Leptoptilus and Phmiicopterus. 



Aa, Front, and Ac, side view of tbat of Phoenicopterus; Ah, front view of that 



of Leptoptilus. 



ankylosed ; there is no pessulus, and the first twenty bronchial rings 

 are incomplete internally. There is also a single pair of intrinsic 

 muscles (fig. 1, Aa, Ac). 



The lungs present nothing remarkable, but the air-cells and their 

 associated septa are strikingly characteristic. 



On slitting open the abdominal wall of a Stork {Leptoptilus, for 

 example) in the middle ventral line, the only viscera exposed are the 

 two lobes of the liver and the ventral portion of the gizzard. Ail 



42* 



