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Hayasaka — Richthofenia in Japan. 



though there are a few corals in the Fusulina limestone. 

 The geological and stratigraphical relations between the 

 latter and the coral limestone are now being studied. 



The above summarizes our knowledge of the pale- 

 ontology of Kitakami mountainland. In this paper I 

 intend to report the occurrence of Richthofenia, an asso- 

 ciate of Lyttonia and Amblysiphonella at several localities 



Fig. 1, 



Fig. 1. — An oblique section of a Biclitlwf enia from Japan 

 size. 



3 times nat. 



in other countries. My material of Richthofenia consists 

 of only one piece of black limestone in which a fragment 

 of the fossil is buried. This was presented to me by 

 Uyemura of the Imperial Geological Survey, in the 

 summer of 1915. By cutting this piece of limestone I 

 got an oblique section of Richthofenia, which is shown 

 by fig. 1. Its specific determination is not possible owing 

 to the fragmentary condition of the specimen. 



Figure 1 shows a thin section cut obliquely through 



