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the North Island, transmitted by my esteemed friend the Rev. William Cotton, M.A., 
whose zealous co-operation in the advancement of the natural history of the remote 
colony which benefits by his more important labours, deserves the warmest praise. 
The portion in question is the left os tympanicum (os quadratum of ornithotomists), 
with the upper or mastoid articular end broken away, but with the orbital process 
and inner part of the articular surface for the mandible entire (Plate XXXI. fig. 7). 
From its size, which is double that of the same bone of the Ostrich (ib. fig. 8), it is 
referable to the Dinornis giganteus. In the breadth and flatness of the articular surface 
(c) for the inner division of the mandibular condyle, it resembles the tympanic of the 
Emeu more than that of the Ostrich ; but in the length and slenderness of the orbital 
process (a) it more resembles the Apteryx (fig. 9, a) than any other existing Struthious 
bird. The corresponding process in the tympanic of the Ostrich and Emeu is shorter 
and broader. The upper articular extremity is wanting in the fossil, but its shape 
may be judged of by that of the cavity in the skull (PI, XVI. fig. 4, 28) adapted for its 
reception. The figures preclude the necessity of further verbal description of the 
present interesting fragment: if the length of the entire skull bore the same proportion 
to the os tympanicum in the Dinornis giganteus as in the Ostrich or Emeu, it could not 
be estimated at less than one foot three or four inches in the stupendous extinct wing- 
less bird of New Zealand; but if the form of the beak should have resembled that of 
the Dodo or approximated to that of the Apteryx, the total length of the skull of the 
Dinornis giganteus would exceed the above-estimated admeasurement. 
Vertebra. 
Through the kindness of Dr, Mackellar I have been enabled to compare and describe 
some remarkably perfect specimens of cervical and dorsal vertebrae of the Dinornis, which 
formed part of a collection of bones obtained by that gentleman in the Middle Island, 
from a superficial turbary formation on the coast, submerged at high tide, near the set- 
tlement at Waikawaite: these specimens are now deposited in the Museum of Natural 
History of the University of Edinburgh. 
The first of these vertebrae (Plate XXXII. figg, 1, 2 & 3) to be noticed is a cervical, with 
all its parts as sharp and unmutilated as if it had been artificially macerated. From 
the absence of a neural spinous process, as well as from the longer and more slender pro- 
portions of the body, compared with any of those described and figured in the pre- 
ceding memoir (pp. 97—99), the present vertebra must have come from a more advanced 
part of the neck, and have belonged to a species at least as large as the specimen in 
PL XVII. figg. 1—3. From the analogy of the Apteryx it might be the eighth or ninth 
cervical, since in that bird the spinous process begins to be developed in the vertebrae 
above and below these ; but the proportions of the vertebra and the analogy of the Emeu 
indicate it to have come from a part nearer the head. 
