EEPOET ON THE EADIOLAEIA. 123 



spherical lattice-shell, enclosing the central capsule, arise two equal, free, radial spines, 

 opposite to each other on the poles of one axis. 



Subgenus 1. Xiphosphoerantha, Haeckel. 



Definition. Pores of the spherical shell regular, of nearly equal size and form ; 

 surface smooth or a little rough, without spines or thorns (other than the two polar spines). 



1. Xiphosphcera planeta, n. sp. 



Pores regular, hexagonal, eight to nine times as broad as the thin bars. Ten to twelve pores on the 

 half equator. Shell very thin walled ; surface smooth. Polar spines three-sided pyramidal, about 

 as long as the axis of the sphere, as broad at the base as one pore. 



Dimensions. Diameter of the sphere 012 to 013, pores 0'016 to 0'018, bars 0'002 ; length of 

 the polar spines 01 to 015, basal thickness 0'02. 



Habitat. Pacific, central area, surface ; Stations 271 to 274, depths 2425 to 2750 fathoms. 



2. XiphospJicera ffcea, n. sp. (PI. 14, fig. 5). 



Pores regular, circular, with prominent hexagonal crests between them. On the half equator ten 

 to twelve pores, of the same breadth as the crested bars. Shell thin walled ; ' surface smooth. 

 Polar spines three-sided prismatic, about twice as long as the axis of the sphere, twice as broad 

 at the base as one pore. 



Dimensions. Diameter of the sphere - 07 to 0'09, pores and bars 0'005 ; length of the polar 

 spines 015 to 0'2, basal thickness 0-01. 



Habitat. Pacific, central area, Station 274, depth 2750 fathoms. 



3. Xiphosphcem vemts, n. sp. (PI. 14, fig. 2). 



Pores regular, circular, with prominent hexagonal frames. On the half equator fifteen to 

 eighteen pores, of the same breadth as the bars. Shell very thick walled ; surface smooth, honey- 

 comb-Like. Polar spines conical, smooth, about as long as the axis of the shell, twice as broad 

 at the base as one pore. 



Dimensions. Diameter of the sphere 012 to 013, pores and bars 0'005 ; thickness of the shell 

 wall 0-013 ; length of the polar spines 012 to 015, basal breadth O'Ol. 



Haitat. Pacific, central area, Station 272, depth 2600 fathoms. 



4. XipJiosphcera luna, n. sp. 



Pores regular, circular, hexagonally lobed or rosette-shaped, three times as broad as the bars. 

 Ten to twelve pores on the half equator. Shell thick walled ; surface smooth. Polar spines three- 

 sided pyramidal, one to two times as long as the axis of the shell, as broad at the base as one pore 



