POEMATIOlSrS AND FOSSILS OF SOUTH MANCHURIA 115 



The specimens illustrated on Plate 26, Figures 2-5, are apparently 

 the same species. They are convex and subsemicircular in outline, 

 with rather slender axes and moderately wider planulated margin. 

 The anterior parts of the axes and pleural lobes are faintly marked 

 by the same furrows, nearly fading away at the inner margin of the 

 doubler. 



The specimen illustrated in Plate 26, Figure 6 (U.S.N.M. No. 

 83774) , is moderately convex, transversely subsemicircular in outline 

 with a convex, broad axial lobe and rather narrow planulated mar- 

 gin. The axis is marked by the three anterior transverse furrows and 

 a very shallow posterior furrow that divides the axis into four rings 

 and a terminal section. The pleural lobes are rather convex and are 

 marked by furrows. 



Formation and locality. — Lower Ordovician, Wuting formation: 

 In the sandy limestone beds on the top of Wu-ting hill, 3 miles south 

 of the Yen-tai colliery, Liao-tung, Manchuria. 



