ARSINOITlIEIilUM. 
29 
slightly concave. The transverse processes are large knobs with rib-facets {t.j .) on 
their antero-lateral surfaces. The anterior zygapopliyses {a.z.) are placed very low, 
little above the level of the top of the centrum. The neural arch rises into a high 
backwarclly directed neural spine (n.sj).), the anterior face of which is formed by two 
Text-fig. 11. 
A X i B X -1 
Anterior thoracic vertebra of Arsinoitherium zitteli : A, from front ; B, from right side. 
a.z., anterior zygapophysis ; c.f., capitular facet ; n.sp., neural spine ; p.z., posterior zygapophysis ; 
t.f., tubercular facet. 5 nat. size. 
Text-fig. 12. 
Middle thoracic vertebra of Arsinoitherium zitteli : A, from front ; B, from right side. 
Lettering as in text-fig. 11. | nat. size. 
surfaces meeting at a sharp angle, while the posterior face is concave ; towards 
the summit the spine tends to become bifid. The anterior capitular facets {c.f.) are 
placed low down on the sides of the centrum, the posterior ones higher up. 
Further back in the series (text-fig. 12) the body of the centrum becomes 
