97 
Vertebra. (Plates XVIL & XVIIL.) 
Of the five vertebree in the present collection, only one is of a size which surpasses 
in a marked degree that of the corresponding vertebra in a full-grown Ostrich ; but 
all present much stronger proportions, especially of the spinous process, which is un- 
usually robust. The largest vertebra’, v1, is a cervical one, probably from below the 
middle of the neck, anterior to those which are distinguished by a median inferior spine. 
The following are its dimensions as compared with the twelfth cervical of a full-sized 
Ostrich :— 
Dinornis. Struthio. 
In. Lin, In. Lin. 
Length, at the middle of the terminal articular surfaces . 2 9 2 oo 
‘Breadth, at the middle of the body . . . . . . . . 1 6 8 
Height of the middle of the body . .. . et a 8 
Height from anterior base of spine to the lower nar of the 
anterior artioular-gurface 2 5 gh 2 3 A ke 8 1 oO 
Lehefh ofthe. neural arch. ase. ee F A 8 «ae ate ED 1 5 
VA ae eS ee Ae ee ee ee: 0 11 
Every process and proininence of this specimen of the vertebre of the Dinornis is 
broken off, with the exception of the right posterior oblique process. The texture every- 
where presents large reticulate cancelli, which communicate with the outer surface by 
an orifice on each side the neural arch, behind the upper transverse process. 
The body of the vertebra is square-shaped, with a broad and flat, or 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 corresponding vertebre 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. 
Two other vertebre belong to the base of the neck, and correspond with those few 
cervical vertebre at that part which, in most birds, have a median inferior process for 
the more advantageous origin of the great longus colli anticus muscle*. These two ver- 
tebree must have come from the same or from closely contiguous parts of the neck ; but 
they present differences of configuration and proportion which prove that they have 
not belonged to the same species of Dinornis. 
Both manifest the generic massive proportions, the squareness of the body, the great 
t Pl, XVII. figs. 1, 2, 3. 
2 None of the cervical vertebrae present this character in the Ostrich or Emeu, but we find it in the last 
cervical of the Rhea, and in the last three cervicals of the Apteryx and Bustard, 
oO 
