PEOFESSOK OWEX ON THE GENUS DIKORNIS. 



157 



shorter than in the fourth (fig. 12, pi). The neural arch attains its greatest length in 

 the twelfth vertebra. The connecting bar (fig. 16, b) of the parial neural spines is 

 slightly raised, and is better defined before and behind by the rough pits for the 

 elastic ligaments than in some of the antecedent cervicals. The breadth of the neural 

 platform across the postzygapophyses is relatively greater, in a small degree, than in 

 the antecedent cervicals ; yet their articular surfaces (fig. 15, iiz) remain longer in 

 proportion to their breadth. The perforation of the interzygapophysial bar continues. 



The longitudinal ridges of the pleurapophysial plate (fig. 15, pi) are more pro- 

 minent ; the upper one assumes more the character of a metapophysis (ib. m). 



The cervical vertebra of Binornis giganteus, figured of the natural size in plate 40, 

 vol. iii. of the ' Zoological Transactions,' is the answerable one to the twelfth in the 

 huger representative species of the South Island of New Zealand. It is less broad in 

 proportion to its length, and thus conforms to the more slender metatarsals cha- 

 racteristic of D. giganteus of the North Island. The transverse connecting bar of the 

 neural spines, marked s in fig. 5 of the plate 40, rises nearer to the summits of the 

 parial divisions ; the ridges continued from these, forward, converging to the fore 

 margin of the neural arch, are longer and broader than in Binornis maximus ; the 

 hollow behind the neural spines is also broader. 



The thirteenth and fourteenth vertebrae in Binornis are most nearly matched by the 

 sixteenth and seventeenth in Struthio camelus, in which species the eighteenth vertebra 



FOURTEENTH VERTEBRA (i natural size). 

 Fig. 17. 



Aspect- 

 Fig. 16, haemal (ventral). 



(fig. 41 ofMivart), like the fifteenth va. Binornis (fig. 19), first changes its parial or 

 double for a single hypapophysis, hy. My figure 17 may therefore be contrasted with 



z2 



