70 THE VOYAGE OF H.M,S. CHALLENGER. 



3. Ethmosphcera polysiphonia, n. sp. (PI. 12, fig. 6). 



Tubuli conical, their outer opening three-fourths as broad as the inner and three times as 

 broad as their height. Sixteen to eighteen pores on the quadrant. Diameter of the outer pores 

 three times as large as their distance apart. 



Dimensions. Diameter of the shell 0'2, outer pores O'OOS, their distance 0'003. 



Habitat. West Tropical Pacific, Station 225, depth 4475 fathoms ; also fossil in Barbados and 

 in Sicily. 



Subgenus 2. Ethmosphceromma, Haeckel. 

 Definition. Tubuli cylindrical, their outer opening about as large as the inner. 



4. Ethmosphcera stenosiphonia, n. sp. 



Tubuli cylindrical, short, quite contiguous, so that their diameter is six times as large as their 

 distance apart, but about equal to their height. Nine to ten pores on the quadrant. 

 Dimensions. Diameter of the shell 014, outer pores 0'012, their distance 0'002. 

 Habitat. Central Pacific, Station 271, surface. 



5. Ethmosphcera pachysiphonia, n. sp. 



Tubuli cylindrical, twice as long as broad, very thick-walled, and nearly contiguous, so that 

 their diameter is five times as large as their distance apart. The thickness of their wall is equal to 

 their lumen. Twelve to fourteen pores on the quadrant. 



Dimensions. Diameter of the shell 016, outer pores O01, their distance 0'002. 



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



6. Ethmosphcera leptosiphonia, n. sp. 



Tubuli cylindrical, short, about as long as broad, very thin-walled and fragile, separated by wide 

 distances, which are three times as large as their diameter. Six to seven pores on the quadrant. 

 (Very similar to Siphonosphcera cyathina, PL 6, fig. 10, but quite regular, all tubuli retaining the 

 same size and distance.) 



Dimensions. Diameter of the shell 012, outer pores O'Ol, their distance 0'03. 



Habitat. North Atlantic, Faeroe Channel, John Murray ; surface. 



7. Ethmosphcera macrosiphonia, n. sp. 



Tubuli cylindrical, very elongated, four times as long as broad ; their bases separated by 

 distances which are equal to their breadth. Eight to ten tubuli on the quadrant. (The tubes are 

 similar to those of Siphonosphcera serpula, PL 6, fig. 6, but quite regular, straight, not curved, all of 

 the same size and at equal distances apart.) 



