XV 



ectethmoid, and sends downwards a curved process, which meets, and is connected with, the 

 maxilla. The postorbital process of the skull is long, and nearly reaches the malar arch. 



The symphysis mandibulee is nearly half the length of the lower jaw. The angle of the jaw 

 is truncated, with a strong, triangular, somewhat recurved process internally. Two small ossicles, 

 apparently similar to those described by Nitzsch * as metagnathia in the Passeres, exist in the 

 fibrous tissue external to the quadrato-mandibular articulation. 



There are fourteen cervical and five dorsal vertebrae, the last dorsal being ankylosed to the 

 sacrum, but carrying a pair of ribs. The fifth, sixth, and seventh cervicals have bony bridges 

 developed between the anterior zygapophyses and the transverse processes. The last two 

 cervicals have well-developed free ribs. There are five pairs of true ribs, of which four articulate 

 with the sternum directly. These four, as well as the last cervical, support uncinate processes. 

 Hypapophyses are developed on the first two dorsal vertebrae. There are eleven sacral and five 

 free caudal vertebrse, these last having, as well as the compressed triangular pygostyle, well- 

 developed transverse processes. The total number of vertebrae is thirty-five, of which nineteen 

 are prsesacral. 



The body of the sternum is triangular, tapering to quite a point behind. Posteriorly it has 

 four very deep notches, extending half the total length of the sternum. Of these the inner pair 

 are wider and bigger than the outer, but not quite so deep. The internal xiphoid process is 

 almost straight and rod-like ; the external one, on the other hand, is expanded at its termination 

 into a large, somewhat falcate tip. The costal process is small, and pointed forward and out- 

 wards. The manubrium is well marked, but not bifurcated. It is keeled anteriorly ; and the 

 anterior margin of the sternum, which in profile is nearly straight, runs onto it. 



The ilia, anterior to the acetabulum, are short and oblique; they are widely separated in 

 the middle line by the co-ossified neural spines of the " sacral " vertebrae. The postacetabular 

 ridge is well marked, ending in the strong posterior iliac spine, which is united by a thin bony 

 bridge with the ischium, nearly at right angles to the axis of the latter. The pubes are slender 

 and recurved ; and, as in most birds which lack the amhiens muscle, there is no prepubic process. 



The clavicles are well developed ; they are convex forwards, and form a U-shaped " merry- 

 thought." There is no backwardly directed hypocleidium at their symphysis ; but the scapular 

 ends are expanded, and moderately compressed, articulating with both scapula and coracoid. 



The first metacarpal has a conspicuous process developed radially, which is covered only by 

 naked skin, and may easily be seen or felt in the fresh bird. The first phalanx of the index has 

 a strong postaxially directed process at its distal end, which articulates with the extremity of the 

 corresponding phalanx of the third digit. The tibia has the cnemial process but very slightly 

 developed. Below, its anterior face has a bony bridge, through which the extensor communis 

 digitorum passes. The anterior aspect of the tarso-metatarse, which bone is very short, not 

 exceeding in length the third basal phalanx of the third digit, is extensively grooved externally. 

 There is a small " calcaneal " process posteriorly at its upper end, grooved by a deep canal for 

 the flexor muscles of the foot. The external articular facet is much shorter than the others ; 

 it is divided into two articular surfaces, and, in accordance with the reversed fourth toe, looks 

 backwards. 



* Zeitschr. f. d. gesammt. Nature, xix. p. 398 [18G2]. 



