176 
BULLETIN OF THE LABORATORIES 
Fiq. 3.' Clathropom frondosa, Hall ; a tangential section. 
Fig. 4. Clathropom Clintonensis, Hall and Whitfield ; a tangential section. 
Fig 5. Ptilodictya expansa, Hall and Whitfield; a, a part of the surface; b, 
a tangential section. 
Fig. 6. Phcenopora platyphylla, James ; a, a part of the surface; b, a tangen- 
tial section. 
Fig. 7. Pcenopora magna^ Hall and Whitfield ; a part of the surface. 
Fig. 8. Paehydirtya emaeiata,, n. sp ; a part of the surface. 
Fig. g. Pachydictya bifurcata., ( Van Cleve) Hall ; a, a part of the surface ; b, 
a tangential section. 
Fig. 10. Lichenalia concenh'ica. Hall ; a part of the surface, where it has been 
worn or emacerated, showing the angular intercellular spaces. Copied from Hall, 
Geol. Surv. Ind. nth Rep., Plate 5, Fig. 6. 
Fig. II. Pachydictya turgida, n. sp ; a tangential section. 
Fig. 12. Rhinopo 7 'a vei'tMcosa, Hall ; a tangential section. 
Fig. 13. Ceramopoi'a expansa^ James ; a few cell apertures, as shown by a part 
of the surface of the type specimens. From a sketch taken from the type specimen 
in the collection of Dr. L. B. Welch. 
Fig. 14. Prasop 07 'a parmula. n. sp ; a, a tangential section ; b, a vertical sec- 
tion. 
Fig. 15. Monotropella confiuens, n. sp ; a, a part of the surface ; b, a tangen- 
sial section ; c, a vertical section. 
Fig. 16. Callopora magnopora; n. sp ; a, a part of the surface ; b, a tangential 
section ; c, a vertical section. 
Fig. 17. Callopora Ohioensis, n. sp ; a, a part of the surface ; b, a tangential 
section ; c, a vertical section 
