Fig. *7. — Sacrum of Triceratops porosus, Marsh, 



(Seen from below, one-eighth natural size.) 



a, anterior face of first sacral vertebra ; /. posterior face of last sacral vertebra ; 



i. neural spine of last vertebra ; 2. anterior zygapophysis of first vertebra ; 



I — 10, transverse processes left side. 



