326 MR. W. K. PARKER ON THE OSTEOLOGY OF BALvENICEPS REX. 



diminishing again in the dorsal region. The pre-zygapophyses are exactly adapted to 

 them, and necessarily look upwards and inwards. The articular surfaces of the centrums 

 maintain their true ornithic character from the axis to the pelvis. The posterior surface 

 of the axis already described has its counterpart in the rest of the post-central facets ; 

 whilst answering to these, those at the anterior end of each centrum are concave from 

 side to side, and convex vertically. This beautifully strong mode of articulation allows 

 of pretty free movement backwards and forwards between any two vertebrae ; but it 

 also permits some motion from side to side. From the third to the fifteenth cervical 

 vertebra (inclusive), there are anchylosed rudimentary ribs or ' pleurapophyses,' and 

 the first pair of these send down the strongest process ; this inferior process of the short 

 rib becomes more pointed and smaller until we reach the eleventh cervical vertebra, 

 where it is obsolete. In this and in the succeeding vertebr8eto the fifteenth the pleura- 

 pophysis scarcely projects downwards beyond the upper and lower transverse processes 

 between which it lies, and to which it is anchylosed. The sixteenth cervical has a 

 short two-headed rib, and that of the seventeenth is only half an inch shorter than the 

 first dorsal rib, but it is narrower, very narrow in the middle, and has no appendage. 

 This short condition of the cervical pleurapophyses is very much like what we find in 

 the Boat-bill, the Herons and the Storks, as also in the Pelican ; but in other Totipal- 

 raatae — e. g. the Gannet and Cormorant — these ' ribs' are very long and styloid, especially 

 in the latter bird, where they nearly reach the lower end of their own vertebra. The 

 Colymbi are like the Cormorant in this respect, and so are the Flamingos, although 

 tliese latter birds have very elongated cervical vertebrae, such as are only found again 

 in the (typical) Herons and the Pelicans. But in the Cranes we have not only the 

 long styliform pleurapophyses, but the tendons of the lateral muscles are ossified and 

 continuous with the base of the small rib and with the diapophyses. These osseous splints 

 are all parallel with eacli other and give a peculiar character to the skeleton of the neck 

 in these birds. The ninth cervical of the Balseniceps (PI. LXVI. figs. 5 & 6) may be taken 

 as of a mediuQi size, and its measurements are as follows :■ — Length 1| inch, breadth 

 across the diapophyses li inch, and thickness at the middle two-fifths of an inch, and 

 depth or height at the same part three-fifths of an inch. The third and fourth cervical 

 are here not so quadrate in shape, seen from above, as in most birds. There is along the 

 upper lateral margin in these two bones a large crescentic notch between the massive pre- 

 and post-zygapophyses ; but in the Adjutant this notch is bounded before and behind by 

 a sharp spur of bone in the third, whilst in the fourth vertebra it is converted into a large 

 oval foramen. This foramen is relatively smaller in the Fowl, but it exists in both the 

 third and fourth joints. In the extremely compressed and elongated cervicals of the 

 Heron, this foramen exists even on the fifth, whilst it is sometimes obliterated in the 

 fourth. The third and fourth cervicals of the Balseniceps have low thick neural spines, 

 marked before and behind by the large tubercle for the elastic ligament. The centrum 

 of the fourth is compressed and has two oblong parallel tubercles beneath, the meaning 



