164 PROFESSOR OWEN ON THE GENUS DINORNIS. 
‘The preaxial surface has its vertical extent not so inferior to the transverse as in 
Struthio. 
The pleurapophysis articulates with a small shallow pit on a very short parapophysis ; 
the ‘head’ is supported on a neck 14 inch long, and slender in proportion to the 
body and tubercular process, which is sent off at an angle of 45’ with the neck; it 
terminates by a smooth round tubercle, fitting a corresponding pit on the lower surface 
SIXTEENTH VERTEBRA (‘ 1st dorsal,’ 3 nat. size). 

Fig. 25, neural aspect. 

Fig. 26, lateral aspect. 
of the diapophysis, which it thus underprops. ‘The body of the rib is flattened, 1 inch 
3 lines broad at the divergence of the cervical and tubercular branches; it is slightly 
curved inward and forward, and gradually terminates in a point. No hemapophysis 
(sternal rib) is developed in the sixteenth (1st dorsal) vertebra of Dinornis maximus. 
In the first dorsal vertebra of D. elephantopus the hypapophysis is more central in 
position, more tuberous, less compressed, with a shorter base; in other words, retaining 
more of the character of that process in the last cervical. 
The seventeenth vertebra, answering to the twentieth or third dorsal in the Ostrich, 
and repeating the character of the hypapophysis in the first dorsal, exemplifies also the 
difference of being the first of the vertebral series, traced from the skull, in which the 
segment, or osteocomma, is completed by a perfect hzmal arch. 
