432 



PROCEEDINGS OF SECTION C. 



drawing illustrative of the same specimen, and fig. 8 shows a cross sec- 

 tion. It is only necessary to fold the warped surface (constituting the 

 organism) into a cone — -as one folds up paper for a ridged filter in the 

 chemical laboratory — .to arrive at the preceding types. The walls, 

 septa, and tabulae are practicaJly identical, whether the shape be turbi- 

 nate or flabellate, and it seems fair to suppose that the central cavity or 

 cup of the former fulfils no essential function in the economy of the animal. 



Fig. G. 



itched section of portion of rim of Bell-shaped C'alice, showing 

 Older (O) and Inner (I) Walls, Septa (S) at,d Tabula. (T) ; and, in 

 top right portion, a surface view of the Layer (L) investing the 

 margin of the rim. (See also Plate B, Fig. \.J 



It seems possible that cross sections of cylindrical rhizoids, such 

 as are here represented, have been set down as separate organisms, as 

 they resemble rather closely the Protopharetra of Bornemann — though 

 the latter are, of course, a distinct genus, and can be distinguished 

 readily from the former structures when well preserved. 



Many of the flabellate types are of large dimensions, with an area 

 of 30 or 40 square inches. The regularity in the distribution of the 

 septa, and the warped character of the expansion, account for the 

 meandering scalariform appearance of cross sections of the genus. 



