347 



may associate, with such a condition of the spinal marrow, less delicate 

 perception, and less energetic muscular action ; and the vertebrae thus 

 confirm the original induction* from the texture of the femur, that the 

 Dinornis was a more sluggish or less active bird than the Ostrich. 



1558. A portion of the os sacrum and anchylosed iliac hones of the Dinornis 

 giganteus. This portion of the pelvis consists of twelve anterior anchy- 

 losed vertebrae of the sacrum, with a portion of the right ilium and ace- 

 tabulum. Of the size of this fine fragment an idea will be conveyed to 

 those who have not seen the original by the subjoined table of its dimen- 

 sions, compared with those in a full-sized Ostrich. 



Dinornis. Struthio. 

 In. Lin. In. Lin. 



Height of the first sacral vertebra 6 10 4 6 



Breadth of the articular surface of the body of ditto .34 18 



Breadth of the seventh sacral vertebra 3 3 13 



Length of the first seven sacral vertebras .... 6 6 69 



The last admeasurement shows that the anterior part of the sacrum, in- 

 cluding the first series of vertebrae provided with double transverse pro- 

 cesses on each side, is shorter in proportion to its height and breadth as 

 compared with the Ostrich ; and these proportions are shown by the 

 smaller specimen, No. 1561, to characterize the entire pelvis in the genus 

 Dinornis. The under surfaces of the first seven vertebrae are flattened, and 

 form a smooth and slightly concave platform in the remaining four. The 

 inferior transverse processes pass out horizontally to the lower border of 

 the ilium, which descends to the level of the under surface of the bodies of 

 the sacral vertebrae. In the Ostrich they ascend obliquely upwards to join 

 the upper transverse processes, before abutting against the lower border of 

 the ilium, which does not descend so low as the bodies of the vertebrae. In 

 the Ostrich the first two inferior transverse processes of the sacrum retain 

 their primitive condition of detached ribs, and three transverse processes 

 succeed them before the commencement of the os pubis-f~. In the great 

 Dinornis the second sacral rib is anchylosed as a transverse process, and 



* See Proceedings of the Zoological Society for November 1839. 



f See description of the sacrum in Birds, in the ' Cyclopaedia of Anatomy,' art. Aves, p. 271. 



2 y2 



