SKELETON OF MARSUPIALIA. 



329 



The metapophyses Avhicli begin to increase in length in the 

 three posterior dorsal vertebrae, attain a great size in the lum- 

 bar vertebrae, and are locked 'into the interspace between the 

 anapophyses and post-zygapophyses. The diapbphyses of the 

 lumbar vertebras progressively increase in length as the ver- 

 tebras approach the sacrum ; they are most developed in the 

 Wombat, where they are 



directed obliquely forward. 211 



In the Kangaroos, Potoroos, /; . \ 



and .Perameles, they are 

 curved forward and ob- 

 liquely downward. The 

 length of these and of the 

 metapophyses is relatively 

 least in the Petaturists, 

 Phalangers, and Opossums. 

 In the Wombat the meta- 

 pophysis rises suddenly from 

 the outside of the prezyga- 

 pophysis of the twelfth dor- 

 sal, increases in length to 



Kangaroo. 



the second lumbar, diminishes by degrees to the second sacral, 

 and is rudimental in the following sacral and caudal verte- 

 brae. A rudiment of the anapophysis is first discernible on the 

 eleventh dorsal : the process gradually increases to the last dorsal, 

 diminishes in the lumbar, and disappears in the last of that series. 

 The diapophysis, moreover, is not suppressed on the last dorsal 

 vertebra. The serial homology of the transverse processes of 

 the lumbar vertebra is here manifested in the most unequivocal 

 way ; both metapophyses and anapophyses coexist with diapo- 

 physes in the last four dorsal and the first three lumbar vertebra3. 

 Whether, therefore, the metapophysis or the anapophysis be the 

 part called ' tubercle ' by some Anthropotomists, neither of them 

 is, in the lumbar vertebrae, .the process named * transverse ' in 

 the thoracic vertebras : that process, to which the name ' diapo- 

 physis ' is restricted in the present work, is continued distinctly 

 into the lumbar region, and is there lengthened out by a super- 



