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affinities of Notornis. Yet the form, so magnified, is so novel and unexpected, that 
the singularity of the occurrence of a Coot, so large as is indicated by the fossils here 
described, makes it incumbent on me to offer a few remarks on the differences obser- 
vable in those birds that, resembling the Notornis in size, come nearest to it in the 
structure of the beak. 
The depth, the degree of compression and the upper convexity of the strong bony 
basis of the upper bill of Notornis, with its almost basal perforation by the nostrils, 
remind us of some of the characters of the great Maccaw’s beak ; but, besides the 
absence of the terminal hook, the superior size of the nostrils, the absence of the bony 
septum narium in Notornis, and the grooved and perforated palatal surface of the pre- 
maxillary, are essential deviations from the parrot-type of beak. It approaches more 
in shape to the upper beak of the Raven, but it is less curved, deeper and more com- 
pressed, and the sides are more vertical ; the nostrils are also smaller, and the palatine 
surface of the Raven’s premaxillary is entire, gently hollowed out, with a median ridge 
instead of a groove. 
The Porphyrio in every particular save size much more closely repeats the characters 
of the skull of Notornis; and the affinity is equally decisively marked in the form 
and structure of the lower jaw. Of this part of the Notornis, the entire ramus of 
the right side and the whole of the symphysis have been fortunately preserved. The 
posterior articular expansion presents above an irregular transverse subrhomboidal 
cavity, with a narrow and long articular surface (a, fig. 13, Pl. XLVII.) extending 
along the outer and hinder border ; and the shorter and broader articular surface (z) at 
the fore-part of the deep central depression. The inner angle rises almost vertically : 
it has a small pneumatic foramen (pn): the back part of the enlargement presents an 
almost flat, irregular, triangular, slightly concave vertical surface; the lower angle (30) 
curves downwards and forwards below the lower border of the ramus. The surangular 
(2, fig. 7) supports a low coronoid process, whose base reaches trom the articular 
enlargement to near the beginning of the sharp alveolar border: its truncated summit 
has two small depressions on its outer side ; they are deeper parts of a more extensive 
external muscular impression, bounded below by a line reaching nearly to the lower 
border of the ramus. This border (fig. 12) is smooth, convex, and of uniform thick- 
hess ; it describes a gentle sigmoid curve, convex on leaving the deflected angle, con- 
cave where it joins the symphysis (s, fig. 7). The coronoid region has three perfora- 
tions ; the posterior one (w) is a small vertical oval, the anterior (u) is a longer 
longitudinal ellipse, and immediately behind this is a linear fissure, which marks part 
of the lower boundary of the surangular (29’). All the elements and both rami of the 
jaw have coalesced, 
The upper border of the ramus (fig. 13) is convex, and a little thickened between 
the coronoid and the beginning of the sharp alveolar ridge: this is continued to the 
point of the symphysis, ss, which is more than one-third the length of the jaw; and 


