MR. W. K. PARKER ON THE OSTEOLOGY OF BAL^ENICEPS REX. 339 



even in very old birds. The same thing occurs in Gannets and in Cormorants. In 

 the Secretary Vulture and in the White Pelican there is this claviculo-sternal articu- 

 lation ; but it becomes anchylosed in old age. In young Cranes — e. tj. Grus antigone — 

 this joint may be seen; but in full age, when the trachea has gone some distance into 

 the sternum, it is entirely obliterated. We have not seen this structure in the some- 

 what aberrant Balearic Crane, nor in the Agami {Psophia crepitans), in which bird 

 unmistakeable Gallinaceous characters are present. But in this young Balaeniceps not 

 only is all trace of a joint gone, but the amount of ossification and the actual strength 

 of this part are very great indeed ; it is a seven-times strengthened anchylosis. The upper 

 surface of the sternum is deeply and evenly concave, its depth in the mid-part being one 

 inch and a quarter, whilst the same part is only a line deeper in the Adjutant. These 

 two birds agree also in the number of large pneumatic holes, especially at the anterior 

 and middle region, and between the five hinges for the hsemapophyses on the upper 

 margin of the sternum. In some of the Storks there are very small rudiments of a pair 

 of sub-mesial emarginations besides the large lateral ones, which are constant. 



In Balaeniceps, however, these notches are nearly half an inch broad, leaving between 

 them a xiphoid mesial process three lines wide at its extreme end. The outer notch is 

 nine lines across, its external outline being the inner margin of the long narrow hypo- 

 sternal process ; the upper and external margin of this process running forwards to the 

 joint for the 'sacral' hsemapophysis, is elegantly sigmoid. The great length of the 

 hyposternal process (twice as long as that of the Adjutant) reminds us very strongly 

 of the Rails and Coots, and still stronger Ralline features will show themselves towards 

 the end of our task. The sub-mesial emarginations (very common in birds, but not 

 present in the typical Ardeina) tell us of another Wader with strangely modified 

 jaws — viz. the Spoon-bill, a bird which seems to stand, in Nature, between the Storks 

 and the Ibises. The very thick strong keel of the sternum passes on to the end of the 

 bone ; in the Totipalmatae — e. g. Pelican, Gannet, &c. — it only reaches half-way. In many 

 birds — e. g. the Boat-bill, Herons, Storks, Cranes, Geese, &c. — the rami of the furculum 

 are flat at the upper end, and passing within the head of each coracoid are there arti- 

 culated. But in many other groups of birds — e. g. the Balaeniceps, Diurnal and Nocturnal 

 Raptores, Swifts, Goat-suckers, and different genera of the Totipalmatae, as the Cormo- 

 rants, Gannets, and Pelicans — the rami of this bone expand and become very thick 

 before passing between the coracoids. In these latter cases the outer thickened part 

 of the furculum forms an oval flat synovial surface which articulates with a similar sur- 

 face on the front of the head of the coracoid, whilst the inner part of the ramus passes 

 on, flat and triangular, to articulate with the inner side of the head of the coracoid. 

 Measured in a straight line the symphysis of the furculum of the Balaeniceps is 3f inches 

 from its inner tip. These upper ends are 3 inches apart and the width across the thick 

 anterior articular processes is 3f inches. It is therefore U-shaped as in the wide-bodied 

 Storks, and not V-shaped as in the flat-bodied Herons. In the Pelican the enlargement 



