Limb-hones ofMassosi^ondyhis {?) Browui. 119 



Cervical Vertebra}. 



Two cervical vertebrai were found in natural articulation 

 with each other, but only the anterior half of the second is 

 preserved. Thej appear to be the axis and the third cervical ; 

 the axis is 2i inches long, remarkably slender, probably 

 narrowed a little by side to side compression ; otherwise it 

 presents a resemblance to the Wlirtembero; fossil, which I 

 regard as the axis of Zanclodon Qaenstedti. No odontoid 

 ossification is shown in the South- African specimen, and the 

 posterior zygapophyses are in a less elevated position and 

 more extended transversely. The neural spine appears to be 

 but slightly developed. The sides of the neural arch 

 converge upward and forward from the flat inclined posterior 

 zygapophyses, which diverge outward and backward, as in 

 ZancIodo7t. They extend as far back as the posterior 

 articular face of the centrum, forming, as in Zanclodon, a 

 W-like notch when seen from above, owing to a slender 

 process being developed between them in the median line. 

 The posterior zygapophyses measure in transverse extension 

 I5 inch; they are triangular in section, being flattened on the 

 underside, on the inner side, and below. Tlie inferior 

 flattening extends laterally for fully 1\ inch, because the 

 zygapophyses extend transversely outward beyond the middle 

 of the centrum for half the length of the vertebra. The 

 centrum is compressed from side to side, is most constricted 

 at the anterior third, has the lateral portions nearly vertical, 

 and the base formed of two inclined surfaces which meet in a 

 sharp median ridge ; but posteriorly the surfaces are rounded. 

 Anteriorly the angles between the lower part of the side and 

 the base are prominently developed, and may have given 

 attachment to slight ribs, though no facets are seen. Tlie 

 face of the centrum in front is subpentagonal and appears to 

 be flattened. The neural canal is much wider than high. 

 There are no indications of anterior zygapophyses. The 

 greatest width of the centrum in front exceeds | inch, the 

 least width where most constricted is | inch, and the width 

 behind, as preserved, is | inch. The height of the vertebra 

 in the middle, as preserved, is If inch. Except in the 

 transverse extension of the zygapophysial processes beyond 

 the inferior part of the neural arch and centrum, there is no 

 character of importance to distinguish this vertebra from the 

 axis of Zanclodon. 



The anterior part of the third vertebra is chiefly remark- 

 able for two features — first, the greatly increased width, ot 

 the centrum, which is 1^ inch. This is partly trie result of 



