SKELETON OF BRUTA. 



401 



includes eleven vertebra, and forms one strong and continuous 

 bony mass along the whole lumbar region. Its total leno-th is 

 two feet four inches, and it gradually increases in breadth 

 to the sacro-iliac union, which is formed by the first, second, 

 and third true sacral vertebra, and there presents its greatest 

 breadth. It then contracts slightly, and, at the sixth and last, 

 expands again to join the ischia, fig. 268, c, with which and 



26' 



Mylodon rohnstus. xc". 



the ilia it coalesces. Its anterior surface is curved both laterally 

 and vertically. The sj^inal canal is very wide, and the foramina 

 passing from it mark the primary segments. Their neural spines 

 form a curved crest, ib. g. There are twenty-one caudal ver- 

 tebrae, fig. 267, cd. The iliac crest is arched, thickened, and 

 rough; the al^e notably expanded. The ischia, after effecting 

 the sacral confluence, at c, arch outward, of slender form, and 

 expand, at h, fig. 268, to join the still more slender pubis, h, 



VOL. II. D D 



