TUPAIID^. 119 



The transverse process is most strongly developed in the 5th lumbar vertebra 

 where it has the most antero-posterior extension, as a thin, almost transparent plate 

 of bone directed much forwards. The process is very small in the 1st lumbar 

 vertebra, and in the last dorsal it is reduced to an obscure ridge above the articula- 

 tion of the rib and disappears in the 12th dorsal. It again shows itself in the 11th 

 dorsal, projecting as an obscure ridge over the head of the rib. It increases in size 

 to the 9th vertebra, after which it maintains a nearly uniform size to the 6th dorsal 

 segment, anterior to which it is more extended outwards, attaining its maximum 

 extension in the 7th cervical. The pleuropophysial plate of the 6th cervical ver- 

 tebra is contracted from before backwards at its base, its free extremity being con- 

 siderably extended in that direction. The pleuropophysial processes occur in the 

 5th and 4th vertebrae, and are directed forwards and inwards, and they can be traced 

 as a ridge ia the 3rd vertebra. The transverse processes of the 1st and 2nd caudal 

 vertebrae are at right angles to the centrum and do not project beyond the lateral hne 

 of the sacrum. They have a moderate antero-posterior extension and are sHghtly 

 dilated at their extremities. The processes of the 3rd and 4th caudals are cmwed 

 backwards, convex anteriorly and concave posteriorly. The 5th of either side 

 forms an almost quadrangular figure, but with concave sides and slightly concave 

 posteriorly. In the succeeding vertebra the concavity of the sides is so great 

 as to reach the centrum, so that only the anterior and posterior extremities of 

 the process remain at either extremity of the vertebra, one directed forwards and 

 the other backwards, becoming very obscure as they are traced towards the ex- 

 tremity of the tail. 



In the lumbar region the metapophyses only become to be distinguished and 

 separate from the zygapophyses about the 1st or 2nd vertebra, and anterior to that 

 they become stronger; but gradually, from the more ventral disposition of the 

 zygapophyses which they follow, they come in contact with the transverse process 

 at the 10th vertebra, and in the 9th are ia close connection with it. They can be 

 traced as far forwards as the 4th dorsal vertebra. The zygapophysis of the 1st sacral 

 vertebra is well developed, and it is succeeded by two small processes on a line with 

 it, one behind the other, suggesting that they are more of the nature of rudi- 

 mentary zygapophyses than metapophyses. In the tail the metapophyses reach 

 their greatest development while ia connection with the zygapojjhysis at the 4th 

 caudal vertebra, and as beyond that segment there are no posterior zygapophysial 

 facets, the metapophysis becomes well marked in a few vertebrao, but rapidly dwindles 

 away as we trace it backwards. 



The anapophyses first show themselves in the 4th lumbar vertebra as small, 

 almost styliform processes, increasiag in size to the 12th dorsal, before which they 

 decrease in size, and are brought into close contact with the metapophyses, but they 

 can be detected as far forwards as the fourth dorsal. 



Hyperapophyses begin to show in the 11th dorsal, iacreasiag ia size to the 4th 

 lumbar, decreasing in size to the 5th, and entirely absent ia the 6th. In the 3rd 

 cervical vertebra of T. belangeri there is a small process corresponding in position to 



