AllSINOITIIERIUM. 
29- 
sliglitly concave, Tlie transverse processes are large knobs with rib-facets {t.f.) on 
their antero-latcral 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 
backwardly directed neural spine {n.sp.), the anterior face of which is formed by two 
Text-fig, 11. 
A X -i B X 1 
Anterior thoracic vertebra of Arsinoiiherium zitteli : A, from front ; B, from right side. 
a.z., anterior zygapophysis ; c.f., capitular facet ; n.sjo., neural spine ; p.z., posterior zygapophysis ; 
t.f., tubercular facet. \ nat. size. 
Middle thoracic vertebra of Arsinoiiherium 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 
