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



twice as broad at the base as one pore. (Very similar to some species of Castanella, PI. 113, l)ut 

 witliout the osculum characteristic of this Phajodarian ; may be easily confounded with it.) 



Dimensions. — Diameter of the shell 0-3, pores 0-015, bars 0'015 ; length of the main spines 0-25, 

 basal breadth 0'03 



Eahitat. — North Pacific (Japan), Station 234, surface. 



Subgenus 2. Heliosphceromvia, Haeckel. 

 Definition. — Pores of the shell irregular, of different size or form. 



10. Heliosph(era 'pohjgonaria, n. sp. 



SheU very thin walled, with thread-like bars and irregular, polygonal pores (having four to eight 

 angles, commonly five to seven) ; eight to ten on the radius. Piadial spines at aU the nodal- 

 points of the network, bristle-shaped ; forty to sixty main spines, as long as the radius, twice as 

 thick as the numerous by-spines, which are not larger than one mesh. 



Dimensions. — Diameter of the shell 015 to 0-2, pores 0-012 to 0-02, bars 0-001 ; length of the 

 main spines O'OS to O'l. 



Habitat. — Central Pacific, Stations 266 to 272, surface. 



11. HeliosphcBva heteracantha , n. sp. 



SheU thin walled, with irregular, polygonal pores, twice to four times as Ijroad as the bars ; six to 

 eight on the radius. Twenty radial main spines, three-sided pyramidal, nearly as long as the 

 diameter of the shell, as broad as a larger mesh ; innumerable bristle-shaped by-spines variously 

 fhstributed on the bars and at the nodal-points of the net ; half as long as the radius. 



Dimensions. — Diameter of the shell 0-12, pores 0-006 to 0-012, bars 0-003 ; length of the main 

 spines 0-1, basal breadth 0-012. 



Habitat. — Equatorial Atlantic, Station 347, surface. 



12. Helios'phcera hyperionis, n. sp. 



Shell tliick walled. Pores irregular, roundish, with polygonal frames, three to six times as broad 

 as the bars ; twelve to fourteen on the radius. Thirty to forty main spines, angular, pyramidal, 

 scarcely as long as the radius and twice as long as the numerous bristle-shaped by-spines. 



Dimensions. — Diameter of the shell 0-24, pores 0-006 to 0-012, bars 0-002 ; length of the main 

 spines 0-1, basal breadth 0-012. 



Habitat. — North Pacific, Station 256, surface. 



13. Heliosphcera elector, n. sp. 



SheU thick walled, with irregular, roundish pores, twice to three times as broad as the bars ; eight 

 to teir on the radius. Twenty main spines, three-sided pyramidal, somewhat longer than the radius 

 and four times as long as the short bristle-shaped by-spines. 



