PROFESSOR OWEN ON THE GENUS DINORNIS. 9 
The proximal phalanx of the inner or second toe, 11. 1, has the contour of the proxi- 
mal articulation cordiform, the apex being superior, the notched base below: it is more 
concave than in the Palapteryx robustus, and the inner and lower angle is as much pro- 
duced as the outer one. A well-marked rough surface extends from each of these angles 
forwards upon the under and outer surfaces of the bone. The vertical channel dividing 
the distal trochlea is deeper than in the Palapleryx robustus, especially at its upper part : 
the more gradual slope from the upper to the inner side of the bone, as contrasted with 
the more vertical outer side, is better marked than in the Palapteryx robustus. The 
inner depression at the distal end for the lateral ligament is deeper than the outer one. 
The second phalanx is characterized by the deep lateral cavities and the prominent 
median vertical ridge forming the proximal articulation, which is also more nearly sym- 
metrical than in the Palapteryx robustus ; the inner division is, nevertheless, the broadest. 
The distal articular surface extends further back upon both the upper and under sur- 
faces of the bone. The ungual phalanx (11. 3) shows the same unsymmetrical character, 
produced by the more sloping inner side and the more vertical outer side, as the proximal 
phalanx (11. 1) does: the inner side terminates below in a ridge; the outer one is rounded off 
into the under surface: this is protuberant near the lateral vascular grooves, which are well- 
marked. The length and slenderness of the ungual phalanx contrast better with the pro- 
portions of the same bone in Palapteryx robustus, than do those of the preceding phalanges. 
The proximal phalanx of the middle toe (111. 1) shows well the characters of length and 
slenderness: its proximal articulation differs from that in the Palapteryx ingens by the 
absence of any median vertical ridge: it is a single shallow concavity, a little deepened 
towards the upper part : each angle between the under and lateral surfaces, at the proxi- 
mal expanded end of the bone, supports a rough triangular prominent surface : the distal 
trochlea repeats the same character of the deep median cleft as in the phalanx 11. 1, but 
the divisions are more symmetrical: the articular surfaces extend further upon the 
upper and under surfaces of the bone than in the Pal. robustus. The second phalanx 
(111. 2) has its proximal articulation divided and adjusted by the development of the 
median prominence to the deeply cleft trochlea of the preceding phalanx : its distal 
trochlea repeats the deep-cleft character. In the third phalanx (111. 3) the distal 
trochlea is much less deeply cleft; and the articular surface of the ungual phalanx 
is correspondingly simplified. This claw-bone (111. 4) repeats the long and slender pro- 
portions of that of the second toe: the lower border of each lateral groove is notched, 
which gives a character something like that shown in the corresponding phalanx of the 
Ostrich (111. 4, Pl. I. fig. 7). 
The proximal phalanx of the outer toe (1v. 1) is shorter and broader in proportion te 
ui. 1 and 1.1 than in the Palapteryr robustus: its proximal articulation is more ex- 
tended transversely, is less notched below and less concave: the inner half has the 
greater vertical extent, its lower angle being produced downwards: the shaft is de- 
pressed and slopes away towards the outer side: the distal trochlea is less deeply cleft 
than in 111. 1 or 11. 1. 
VOL. IV.—PART I. c 
