Plate 19 



Page 



Figure 1. Aninnoccms tcichcrti, new species Si) 



A polished, vertical section in a lateral direction across the 

 conch, exposin.ii: the structure of the siphuncle. (See also 

 ]il. 40. fig. 6.) 

 Middle Ordovician. Ssuycu formation : Limestone block, Niu- 

 hsin-tai. Liao-tung. Manchuria. 

 2—1. Anuciioccras iiuirakaniii (Kobayashi) ? 91 



2, A polished, vertical section in a dorsoventral direction 

 across the conch, showing the structure of the siphuncle. 



4, Cross section of the same specimen at its middle, showing 

 the relative size and location of the sipliuncle. 



Middle Ordovician, Ssuyen formation : Limestone near 

 Wu-hu-tsui. Liao-tung, Manchuria. 



3, A partly polishetl. vortical section. 



Middle Ordovician. .Ssuyen formation: Limestone south- 

 west of ren-hsi-liu, Liao-tung, Manchuria. 

 0-8. Armcnoceras manchurense (Kobayashi) 90 



6, 8, Two polished, vertical sections in a lateral direction 

 across the conch, showing the structure of the siphuncle. 



7. Cross section of the same specimen as Figure 8 in its 

 upper part showing relative size and location of the 

 siphuncle. 



Middle Ordovician. Ssuyen formation: Limestone near Pen- 



hsi-hu, Liao-tung, Manchuria. 



9. ArmcnoccraH .species undetermined 101 



Specimen weathered so as to show a part of the ventral side 



of the siphuncle. 

 Middle Ordovician, Ssuyen formation : Limestone near 



Miyanohara, Liao-tung, Manchuria. 



n, 10. Armenoceras magnitnhidatum, new species 91 



10, An oblique vertical section in a lateral direction across 



tile conch, showing the structure of the siphuncle. 



5, Transver.«e section of the same specimen, .showing the 

 relative size and location of the siphuncle. 



Middle Ordovician, Ssuyen formation : Limestone near Niu- 

 lisin-tai, Liao-tung, Manchuria. 

 126 



