ON SOME FOSSILS FROM THE ISLANDS OF FORMOSA & RIU-KIU. 13 



Operculina complanata, (Defeance). 

 (Plate I, figs. 3 and 5, Plate III, fig. 3.) 



Lenticulites complanata, Defrance : Bid. Soi. Nat., 1822. 



Vol. XXV, p. 453. 

 Operculina complanata, Orbigny : Ann. /Sei. Nat., 1826. 



Vol. VII, p. 281, PL XIV, figs. 7-10. 



The Operculince from the Biü-Kiü material are numerous 

 and very interesting. In some cases the rock specimens described 

 as from " raised coral reefs " are very largely composed of them 

 and the reef at Kamé-zu on the south coast of Tokuno-shima 

 has yielded the gigantic specimen shown on Plate I. Figs. 3 and 

 5, a specimen which in its unbroken condition, must have been 

 one of the largest Operculines yet known. Fig. 5 gives the exact 

 present size of this noteworthy specimen and the dotted line 

 indicates what its dimensions must have been before the later 

 chambers had been for the most part broken away. Some part 

 of these later chambers have been destroyed since the specimen 

 came into our possession. In order to determine the fossil at all 

 we were obliged to grind away each surface so as to render the 

 interior chambering visible. The irregularity and brittle character 

 of the test made it impossible to proceed as far as could have 

 been desired with the grinding process but enough has been done 

 to allow of a photograph being taken which shows clearly the 

 Operculine chambers. 



We have considered it best on the whole to refer these 

 examples to the species complanata because they undoubtedly 

 belong to the group of which 0. complanata (Defrance) may 

 be taken as the type. At the same time we think there has 



