62 THE VOYAGE OF H.M.S. CHALLENGER. 



and transparent, except the central dark globular nucleus. The same shells also occur in some 

 mounted preparations of surface organisms from the Challenger. 



Dimensions. Diameter of the shell 012, of the pores 0'012. 



Habitat. Indian Ocean, Ceylon, Haeckel ; Central Pacific, Stations 266, 271, surface. 



2. Cenosphcera inermis, Haeckel. 



Heliosplicera inermis, Haeckel, 1862, Monogr. d. EadioL, p. 351, Taf. ix. fig. 1. 



Surface of the thin-walled shell smooth. Pores regular, hexagonal, twelve to fifteen times as 

 broad as the bars, seven to nine on the quadrant. 



Dimensions. Diameter of the shell 0'08 to 012, pores 0'012 to 0'015, bars O'OOl. 

 Habitat. Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface. 



3. Cenosphcera hexagonalis, n. sp. 



Surface of the thick-walled shell smooth. Pores regular, hexagonal, five to six times as broad 

 as the bars, six to eight on the quadrant. 



Dimensions. Diameter of the shell 01 to 015, pores O'Ol to 0'012, bars 0'002. 

 Habitat. Central Pacific, Stations 265 to 274, at various depths. 



4. Cenosphcera mellifica, n. sp. (PI. 12, fig. 9). 



Surface of the thick-walled shell smooth. Pores regular, circular, with thin hexagonal frames, 

 four times as broad as the bars, six to eight on the quadrant. 



Dimensions. Diameter of the shell 0'2, pores 012, bars O'OOS. 

 Habitat. South Pacific, Station 288, surface. 



5. Cenosphcera favosa, n. sp. (PI. 12, fig. 10). 



Surface of the thick-walled shell rough. Pores regular, circular, with thin hexagonal frames, 

 three times as broad as the bars, ten to twelve on the quadrant. 

 Dimensions. Diameter of the shell 0'2, pores 0'09, bars 0'003. 

 Habitat. North Atlantic, Fierce Channel (Gulf Stream), John Murray, surface. 



6. Cenosphcera vesparia, n. sp. (PL 12, fig. 11). 



Surface of the thick-walled shell smooth. Pores regular, circular, with thick hexagonal frames, 

 twice as broad as the bars, ten to twelve on the quadrant. 



Dimensions. Diameter of the shell 0'25, pores O'OIG, bars O'OOS. 

 Habitat. Central Pacific, Station 265, depth 2900 fathoms, and surface. 



