202

178

vated, but the lateral grooves are not defined as in Notornis. The differences between
the beak of this genus or of Porphyrio and that of Ocydromus are those of proportion.
The whole beak is longer and more slender relatively to the cranium in Ocydromus ;
and this length is gained by the elongation of the nasal part of the beak, or that which
is perforated by the external nostrils, and of the part between the coronoid portion and
the symphysis in the lower mandible.

One may also follow minor traces of resemblance in the cranial part of the skull of
Ocydromus, e.g. in the flat square formed by all that part of the basis cranii included
between the postfrontals and paroccipitals ; in the proportions of the postfrontal and
mastoid ; in the orbits scarcely at all impressing the under and fore-part of the cranium ;
and in the relative extent of the temporal fossae, although the lower boundary of these is
not developed into a vertical ridge as in Porphyrio. But, on the other hand, Ocydromus
more resembles Notornis in the relative breadth of the occipital regions than Porphyrio
does. The chief characters of the skull by which Ocydromus and tribonyx resem-
ble Notornis, are participated in by the European, Australian, and African Rallisae ;
but in the forms and proportions of the upper and lower bones of the beak, the
Porphyrio of all existing birds makes the nearest apprach* to Notornis.

Upper mandible of Nestor. Kea (handwritten)

A second, possibly extinct, species of bird indicated by portions of the skull in Mr.
Walter Mantell's collection is plainly referable to the family of Parrots (Psittacidae),
and particularly to the genus Nestor. The bony portion of the upper beak (Pl. XLIV.
figs. 11, 12, 13), - the only part of the skull preserved, - by its deep, subcompressed,
curved and pointed form, its seeming solidity, pierced by small subcircular nostrils (n)
close to its base, and impressed by the transverse articular fossae behind the palatine
plate of the premaxillaries for the true palatine bones, attests the family character ;
whilst the proportional length as compared with the depth, the narrow upper surface
wo where it suddenly expands above the nostrils to join the cranium, the oblique
depression on the outer surface of the beak leading to the external nostril, the very
narrow elongated triangular palatal surface, with the median linear notch at ist base,-
all demonstrate that in this characteristic part of the skull, the New-Zealand bird
represented by it most resembeled the genus Nestor, a singular nocturnal Parrot, at
present only known as a denizen of that island ; where it is represented by species not
inferior in size to the one indicated by the bony portion of the upper beak. By the
kindness of Mr Gould I am enabled to give figures of the upper mandible (figs. 14,
15, 16) of the Nestor hypopolius to compare with the fossil.