PROFESSOR OWEN ON THE GENUS DINORNIS. 313 



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 XXXIX. 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. XXXVIII. 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. 



Vertebrcs. 



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 XL. 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 former 

 memoir (Zool. Trans, vol. iii., PI. XVIII. , pp. 259 — 261), 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 PI. XVIII. 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 vertebrae 

 and the analogy of the Emeu indicate it to have come from a part nearer the head. 



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