872 



5586. The third lumbar vertebra. 



That of the Esquimaux differs from it chiefly in the retention of the anapophyses. The 

 zygapophyses are less widely apart in the Esquimaux. The distance between the zygapo- 

 physes in each pair is the same in the Australian as in the European, although the vertebra 

 itself is smaller in the Australian. 



5587. The fourth lumbar vertebra. 



The zygapophyses are relatively larger than in the Esquimaux, and the whole neural arch 

 with its processes are larger in proportion to the centrum than in the Australian ; the spine 

 more particularly is longer. This vertebra differs from the foregoing in the reappearance of 

 the anapophysis upon the back part of the base of the diapophysis. Three ridges radiate 

 from it ; one to the diapophysis, another to the anterior zygapophysis, a third to the side of 

 the neural arch. 



5588. The fifth lumbar vertebra. 



The posterior zygapophyses are larger and wider apart than in the Esquimaux, and are 

 larger but not wider apart than in the Australian : the spine is longer than in either of those 

 varieties : the diapophyses are much thicker than in the Australian. The fifth differs from 

 the fourth lumbar vertebra chiefly hi the shortening and thickening of the diapophyses, at 

 the back part of which the anapophyses are reduced to tubercles. The metapophyses now 

 appear as simple thickenings upon the upper border of the anterior zygapophyses. The 

 posterior zygapophyses are larger ; their articular surface is concave, and looks more directly 

 downwards. The neural spine is reduced, particularly in antero-posterior extent. 



5589. The sacrum. 



It consists of six anchylosed vertebrae, the supplemental one being at the caudal extremity 

 of the bone. The first vertebra of the coccyx has nevertheless its usual size and shape : the 

 sacrum is consequently longer in proportion to its breadth than in the Esquimaux, and larger 

 in all dimensions, with a deeper anterior concavity, than in the Australian. The so-called 

 transverse processes of the first sacral vertebra slope more downwards from the anterior arti- 

 cular surface of the centrum than in the Esquimaux, the direction being more like that in the 

 Australian. The anterior zygapophyses also resemble those of the Australian in being larger 

 and more sessile than in the Esquimaux, and the tuberosity which extends outwards and for- 

 wards from their base is much less produced than in the Esquimaux. The articular surface 

 for the ilium terminates on the same transverse line with the third sacral foramen, as hi the 

 Australian. In the Esquimaux it extends very little beyond the second sacral foramen. In 

 the present sacrum the neural arch is completed over four vertebrae and supports a spine : in 

 the last two sacral vertebrae the neurapophysis coalesces with its homotype of the contiguous 

 vertebra, but not with its fellow in the same vertebra. 



