90 THE FAUNA OF THE DEEP SEA 



in wliich respects they strikingly resemble the fossil 

 Radiolaria of Barbadoes and Nicobar islands.' The 

 Ph^eodaria are very widely distributed over the floor 

 of the ocean, and occur in some districts in such 

 numbers that the ' Challenger' was able to bring home 

 some hundreds of thousands of specimens. They are 

 distinguished from other Radiolaria by the thick outer 

 and thin inner capsule, by the typical main opening 

 or atropyle placed on the oral pole of the main axis 

 with a radiate operculum provided with a tubular 

 proboscis, and lastly by the presence 

 of the phgeodium, a voluminous pig- 

 ment body which lies invariably on 

 the oral half of the calymma and 

 is composed of numerous singular 

 pigment granules of green, olive, 

 16. 9.S^,nen. brown, or black colour, 

 rfof theX'i There are many gerrera belong- 



ttotsf i!'phJ: i"g to th« Foraminifera that are 

 dium; B, central probably inhabitants of abys- 



capsule; C, strands ./ i ./ •/ 



of protoplasm in ^^^^i (depths, but they do not seem 

 the calymma. ^ "^ 



After Haeckel. ^^ possess any Special characters, 



unless it be a greater thickness and density of 

 their shells, to distinguish them from their shallow- 

 water allies. 



