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 sheU 0-12, of the pores 0-012. 



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



2. Cenosphcera inermis, Haeckel. , 



Heliosphoera 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 0-12, pores 0-012 to 0-015, bars 0-001. 

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



3. CenosphcBra 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. 



Dimetisions. — Diameter of the shell O'l to 015, pores 001 to 0-012, bars 0*002. 

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



4. Cenosphcera mellifica, n. sp. (PL 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 0'12, bars 0-003. 

 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 tlie shell 0-2, pores 009, bars 0-003. 

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



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



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

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



Dime7isions. — Diameter of the shell 0-25, pores 0016, bars 0-008. 

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



