HERODIONES 439 



is also stork-like in the fact that there is no membrana tym- 

 paniformis ; the bronchial rings are complete rings from the 

 very first. 



The main peculiarity of the windpipe, however, lies in 

 the fact that from a point about three inches from the larynx 

 it appears to bifurcate and to consist of two closely applied 

 tubes. By cutting windows it was ascertained that this 

 appearance corresponded to the reality — that the windpipe 

 did consist of two tubes. This arrangement, which seems to 

 characterise the present species only, is, of course, suggestive 

 of the median tracheal septum of the penguins, &c.^ 



Of the ibises I have examined the windpipe of Eudocimus 

 ruber, E. alba, and of Ibis cethiopica. There are differences 

 between the species similar to those which exist between the 

 species of Platalea. In Ibis cethiopica there is no membrana 

 tympaniformis,the bronchial rings beiiig complete. In the two 

 other species this structure is present, and moreover the last 

 few tracheal rings are defective in the middle line posteriorly. 



The extrinsic pair of muscles are attached in E. ruber to 

 the inner surface of sternum not far from the middle line. 

 The intrinsic muscles stop short some way in front of the 

 syrinx. 



In Platalea ajaja cervical vertebrae 7-10 have a cata- 

 pophysial canal. Some of the dorsal vertebrae are fused. 



The number of cervical vertebra is seventeen or eighteen 

 {Platalea ajaja). The sternum is two-notched {Platalea) 

 and has a small spina externa, but no spina interna. 



The skull has, as in charadriiform birds, ^ a pair of 

 occipital vacuities. 



It is schizorhinal and has rudimentary basipterygoid 

 processes, which in Platalea ajaja have the form of small 

 sharp thorns. Supra-orbital impressions are feebly developed. 

 The lacrymals with the ectethmoids very nearly form a com- 

 plete ring of bone, the aspect of this part of the skull being 



' Gadow, in Newton's Diet. Birds, speaks of the trachea {suh voce) of Platalea 

 as divided by a cartilaginous septum. I have not found this to be the case 

 with P. ajaja or P. leucorodia. 



" Also, however, in geese. 



