SKELETON OF BRUTA. 395 



the aifording a firm fulcrum or centre to the powerful muscular 

 forces exercised by the limbs in the act of burrowing. The 

 elongated metapophyses have a more direct relation to the sup- 

 port of the carapace, the spinous processes representing the 

 ' king-posts,' ib. n, and the metapophyses the * tie-beams,' ib. m, 

 in the architecture of a roof. The sacral vertebra) progressively 

 increase in breadth after the second, to form an extensive junc- 

 ture with the ischial bones. The tuberosities of the ischia, 

 fig. 260, 63, and similar tuberosities at the fore-part of the ilia, 

 fig. 277, 62, bend outward and upward, to afford four strong 

 additional supports to the bony carapace : the long diapophyses 

 of the first caudal vertebra abut ao;ainst those of the last sacral 

 vertebra and the tuberosities of the ischia. The metapophyses 

 reappear upon the second caudal vertebra, and continue to the 

 antepenultimate one, where they are reduced to ridges upon the 

 anterior zygapophyses. H^mal arches, with short terminally ex- 

 panded and flattened spines, are present beneath the intervals of 

 many tail-vertebrae. In Ghjptodoji the caudals coalesce. 



The posterior dorsal ribs are deeply excavated upon their 

 external surface ; five pairs directly join the sternum, which 

 consists of six bones, a very small one being interposed be- 

 tween the fourth and the long one supporting the ensiform carti- 

 lage. 



In the Cape Anteater {Orycteropus), the vertebral formula 

 is: — 7 cervical, 13 dorsal, 8 lumbar, 6 sacral, and 25 caudal: 

 anchylosis is limited to the sacral region : the cervical transverse 

 processes overlap each other ; the costal part of the sixth is a 

 broad plate. The dorsal and lumbar neural spines are much 

 longer than those of the cervical, and are subequal : they slightly 

 converge to that of the twelfth dorsal, which is vertical, indicating 

 a greater extent of inflection of the trunk than in the South 

 American Anteater ; increased freedom of motion is likewise 

 favoured by the less complex character and mode of union of the 

 vertebrae. An accessory tubercle is developed upon the diapo- 

 physis of the seven anterior dorsal vertebra?, which divides near 

 the eighth into metapophysis and anapophysis. These progres- 

 sively increase and diverge from one another in the succeeding 

 dorsals, and in the first lumbar vertebra the metapophysis pro- 

 jects upward, outward, and forward upon the outside of the 

 anterior zygapophysis ; whilst the anapophysis extends backward 

 from the back part of the diapophysis, which it equals in length. 

 The anapopliysis decreases in size in the following lumbar verte- 

 bnc and disa[)pears in the last ; the meta[)ophysis also decreases 



