Plate 34 



Page 



Figures 1-8. Orthis shensiensis, new species 42 



1^, Exteriors of four pedicle valves. 

 5-8, Exteriors of four brachial valves . 

 Ordovician : Huang-pa-yi, Shensi, China. 



9-12. Dalmanella testudinaria (Dalman) 44 



9, 10, Exterior and interior of the same brachial valve. 

 11, 12, Exteriors of brachial and pedicle valves. 

 Ordovician : Near Chao-tien, Szechwan, China. 



13-21. Polytoechia chinensis, new species 48 



13, 14, Two views of the apex of a pedicle valve. 

 15, 16, Exterior and anterior views of a pedicle valve. 

 17, 18, A transverse section and diagrammatic illustra- 

 tion of the same specimen showing the spondylum. 

 19, 20, Exterior and interior views of another pedicle 

 valve. 



21, An exterior view of a brachial valve. 

 Ordovician : Near Huang-pa-yi, Shensi, China. 



22-24. Rafinesquina puteata, new species 45 



22, 24, Exterior view of a pedicle valve and an enlarge- 

 ment (X 4) of the apex, showing fine series of pits. 



23, Exterior of another incomplete ipedicle valve. 

 Ordovician : Near Huang-pa-yi, Shensi, China. 



141 



