Plate 11 



Page 



Figures 1-3. ^tromatoceriiim rc(julnttnn. now species 40 



1, 2, "Weathered specimen showing the characteristic con- 

 centric laminae of the horizontal and vertical sections. 

 3, Polished vertical section of anotlier specimen, showing 

 the radiating pillars. 



4-G. rhnifairia cf. deltoidea (Conrad) 46 



Dorsal, anterior, and lateral views of a pedicle valve. 



7, 8. C'<iiiiarocl(i<U(i plirna. new species 40 



Rock frajj:ments composed almost entirely of the branches 

 of this sponge and a section (X SO) exhibiting the 

 internal structure. 

 Middle Ordovician. Ssu.ven formation : Black banded 

 limestone, in the vicinity of Pen-hsi-hu, Liao-tung, 

 Manchuria. 

 118 



