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 foss, although the lower boundary of these is 
not developed into a vertical ridge as in Porphyrio. But, on the other hand, Ocydromus 
more resembles Wotornis in the relative breadth of the occipital region 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 Rallide ; 
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. K f oy 
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 (Psittacide), 
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 fosse 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 
to 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 its base,— 
all demonstrate that in this characteristic part of the skull, the New-Zealand bird 
represented by it most resembled 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. 

