176 DE. J. vox HAAST ON A NEW SPECIES OF DINOENIS. 



Pelvis. 

 Sir Richard Owen, in part xxiii. of his memoirs on Dinornis, read on January 3rd, 

 1882. before this Society, has described the pelvis of Binornis parvus, obtained 

 in a cave in the provincial district of Nelson. This pelvis is in a perfect state 

 of preservation, and has therefore given ample scope to that illustrious naturalist 

 for an excellent and exhaustive description of that imj-iortant bone. Unfortunately 

 the pehis of Binornis oweni is in a rather fragmentar\- condition, but is sufficiently 

 perfect to show that, while closely agreeing with Binornis imvvus in possessing 

 a true dinornithic type, some of its minor characteristic features have been modified 

 to a small extent, owing to the form and size of the species under consideration. 

 Thus in comparing the pelvis oi Binornis otveni with that oi Binornis parvus, we find, 

 allowing for difference of size, that the former is more massive and broader in pro- 

 portion to its length, and that the cavity of its acetabulum is much wider than in the 

 latter. The following measurements that could be made confirm this statement : — 



inches. 



Breadth (across fore end) 1'95 



Depth or vertical diameter anteriorly 2-20 



Vertical diameter of acetabulum 1'06 



Horizontal diameter of acetabulum without trochan- 

 terian surface 100 



The ilium, principally in front of the acetabulum, is much broader in proportion to 

 length, and consequently the upward slope is not so steep as in Binornis parvus. The 

 ribs belonging to the first and second sacrals have not been preserved, but the articular 

 surfaces for them still exist. The third sacral has no anchylosed ribs as in Binornis 

 parvus ; a pleurapophysis on both sides is substituted for them, in that respect resem- 

 bling the two following ones ; while the sixth and seventh sacrals have their pleura- 

 pophyses united in one thick, short process in the same manner as in Binornis parvus 

 and the other Dinornithida;. 



In the pelvis of Binornis parvus, figured by Sir Richard Owen, the parapophyses and 

 costal elements are wanting in the eighth, ninth, and tenth sacrals, but appear again 

 in the eleventh. In a pelvis of the same species (now in the Canterbury Museum), 

 obtained in perfect condition in a limestone cave of Southern Nelson, and agreeing as 

 to dimensions and form with the above-mentioned bone, the parapophysis belonging 

 to the eleventh sacral exists only on its right side, a minute protuberance of bone 

 indicating this process on the left side only. The parapophyses, therefore, begin on 

 both sides only with the twelfth. In Binornis oweni the parapophyses of the eleventh 

 sacral are missing on both sides, and only the twelfth and thirteenth possess them, 

 coalescing as usual at their distal end. Though the fourteenth sacral exists, the 

 parapophyses have been destroyed. The breadth of the sacral vertebrae is much 



