Plate 14 



Page 



FiGUEE 1. SactoGcras inaii, new species ■ 70 



A polished vertical section in a lateral direction across the 



conch, exposing the structure of the siphuncle. 

 Middle Ordovician, Ssuyen formation : Limestone near Pen- 

 hsi-hu, Liao-tung, Manchuria. 



2. Armenoceras tani (Grabau) 99 



A partly polished vertical section in a lateral direction 



across the conch, showing the structure of the siphuncle. 



Middle Ordovician, Ssuyen formation : Limestone near 



Wu-hu-tsui, Liao-tung, Manchuria. (See also pi. 21, fig. 



7, and pi. 40, fig. 3.) 



3,4. Cijcloceras (?) peitoutzense Grabau 72 



3, A natural vertical section showing a part of the siphuncle. 



4, A polished vertical section, showing the siphuncle. Middle 

 Ordovician, Ssuyen formation : Limestone near Niu-hsin- 

 tai, Liao-tung, Manchuria. 



5. Ormoceras species undetermined 107 



A somewhat oblique natural vertical section. 

 Locality same as Figure 1. 



6. Sactoceras kobayasMi, new species ; 74 



A polished vertical section in a dorsoventral direction across 

 the conch, exposing the structure of the siphuncle. (See 

 also pi. 40, fig. 8.) 

 Locality same as Figure 1. 



7. Cycloceras aokii, new species 70 



A polished vertical section in a lateral direction across the 



conch, exposing the structure of the siphuncle. 

 Locality same as Figure 1. 

 8,9,12. Cycloceras (?) manc/mn'ense, new species 68 



8, A polished verticle section. 



9, A transverse section of the same along the lower part of 

 the specimen, showing the relative size and location of 

 the siphuncle. 



Locality the same as Figures 3 and 4. 



12, A lateral view showing the annulations, with ventral out- 

 line on left. 

 Locality same as Figure 1. 



10. Sactoceras Uaotimgense, new species 76 



A polished vertical section through the conch in a lateral 

 direction, exposing the structure of the siphuncle. 



Middle Ordovician, Ssuyen formation : Limestone on Fu- 

 chin-kou ridge, Liao-tung, Manchuria. 



11. Sactoceras species undetermined 77 



A polished vertical section in a lateral direction across the 



conch exposing the structure of the siphuncle. 

 Locality same as Figure 1. 



13. Sactoceras niitJisinense, new species 75 



A partly polished vertical section showing some of the siphun- 

 cle. ( See also pi. 40, fig. 18. ) 

 Locality same as Figures 3 and 4. 



121 



