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slightly concave under surface : the anterior part of this surface is divided 

 from the anterior articular surface by a transverse channel, that surface 

 being raised to a higher level. This structure does not exist in the cor- 

 responding vertebrae of the Ostrich : it is slightly indicated in those of 

 the Apteryx. The spinal canal presents the usual infundibular expansion 

 at both extremities: it is not larger at its middle contracted part than in 

 the Ostrich. The remains of the base of the spinous process show this 

 to have been almost square-shaped, and much thicker relatively as well 

 as absolutely than in the Ostrich. 



1554. A posterior cervical vertebra of a large species of Dinornis, probably 



Din. ingens. It corresponds with those few cervical vertebrae at the base 

 of the neck, which have a median inferior spinous process for giving a 

 more extensive and advantageous origin to the great longus colli anticus 

 muscle : it manifests the same massive proportions, squareness of the 

 body, great breadth of its under surface, and thick four-sided spinous 

 process as the foregoing vertebra. 



1555. A posterior cervical vertebra of another large species of Dinornis, pro- 



bably Dinornis struthoides ; it is narrower in proportion to its length 

 than No. 1554, but has a thicker spinous process, which, at the same 

 time, is more compressed from behind forwards : the cavity behind the 

 spine is deeper and more angular, as is also the notch between the pos- 

 terior oblique processes. The anterior articular processes are raised 

 higher above the body in the more robust vertebra, No. 1554. The an- 

 terior articular surface of the present vertebra has a much less vertical 

 extent than in the thicker vertebra ; and the inferior spine is narrower, 

 but of greater antero-posterior extent, and is situated nearer the posterior 

 part of the body. 



1556. The cast of an anterior dorsal vertebra of a large species of Dinornis, 



probably Dinornis ingens : it is either the first or second of the dorsal 

 series : the inferior transverse processes manifest part of the concavity 

 for the articulation of the head of the rib, and there is a spinous process 

 from the under surface of the body of the vertebra, which, as in the an- 

 terior dorsal of the Apteryx, is less broad and flattened than in the ante- 



2 Y 



