213 
form formed by the coalesced prefrontals: from the outer border of this platform, a bony 
plate descends and blends with the interorbital septum, half-way down, leaving an 
interval between the septum and the upper part of the plate, through which the olfac- 
tory nerves were continued. The posterior turbinals were attached to the fore-part of 
these descending plates. The interorbital septum is perforated anterior to the common 
outlet of the optic nerves, is deeply grooved at its upper part by the olfactory nerves, 
and is formed below by the presphenoidal prolongation. 
In all other respects in which a comparison can be instituted with the less complete 
cranium of the Notornis described in a previous Memoir, the present specimen agrees 
with it: the part conjecturally restored in Pl. XLVIIL. is shown by the present specimen 
to be correct as to extent. 
The number of skulls of full-grown large terrestrial birds of New Zealand that have 
now been described, clearly indicate at least four species, independently of the one with 
the remarkable occiput, referred to Dinornis proper at p. 154, but more probably be- 
longing to Aptornis, and also of that on which the genus Notornis was founded. The 
rich development of the wingless family of birds, not in individual magnitude only, 
but in the number of species, thus progressively receives additional illustration. 
Owing, however, to the remains of these great birds reaching England for the most 
part in a detached or disconnected state, -few portions of the skeleton of one and 
the same bird having yet been discovered in juxtaposition, or so transmitted to this 
country, and not any specimen, so far as I can learn, having been found with the 
head,—the skull can only be restored to the other parts of the skeleton of species 
already described, conjecturally ; and much remains to be done before such conjectures 
can acquire a degree of certainty. That, however, which is mainly necessary to be 
done, is to record with accuracy and depict with fidelity the several materials for the 
reconstruction of these apparently extinct species of large wingless birds as they from 
time to time reach this country: and the desired result will without doubt in time be 
gained. 
