498 INDEX 



Yohoia — Continued. page 



tenuis Walcott, new species described 172 



figured, pi. 29, figs. 7-13 218 



alimentary canal of 173 



appendages 172-173 



compared with Waptia fieldcnsis I73 



with Yohoia plena I73 



resemblance to Habelia optata 202 



stratigraphic position and association 152 



Young, A. A., specimens of Climactichnites yoimgi from 260 



youngi, see Climactichnites. 



Zacanthoidcs, listed in stratigraphic section Z2)7 



spinosus Walcott, listed in stratigraphic section 337 



sp. undt., listed in stratigraphic section 338 



zenobia, see Micromitra. 



Ziphosuridse, relation to Merostomata 165 



Zoology, Lankester's Treatise on, classification outlined in 153 



zoppii, see Olenopsis and Olenus. 



