REPOET ON THE RA.DIOLARIA. 135 



6. StylosjjJicera dixijphos, Haeckel. 



Haltomina diriiplws, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 83; 



Mikrogeol., Taf. xxii. fig. 31. 

 HaJiomma dixyphos, Haeckel, 1862, Monogr. d. Radiol, p. 433. 



Eadial proportion of the two spheres = 2:l. Cortical shell thin walled, smooth, with regular, 

 circular pores, twice as broad as the bars ; ten to twelve on the half equator. Polar spines about 

 as long as the axis of the outer shell, three-sided pyramidal, at the base twice as broad as one pore. 

 (The two spheres connected by four beams, two opposite in the main axis, two opposite in the 

 equatorial axis.) 



Dimensions. — Diameter of the outer shell 01, pores O'Ol, bars 0-05 ; inner shell 0-05 ; length 

 of the polar spines 0-08 to O'l, basal breadth 0-02. 



Habitat — South Atlantic, Station 332, surface ; fossil in Tertiary rocks of Sicily. 



Subgenus 2. StylosiihcBrella, Haeckel. 



Definition. — Pores of the cortical shell regular, of nearly equal size and similar 

 form ; surface thorny or spiny. 



7. Stylosplmra setosa, Ehrenberg, 1872. 



Siylosphmra setosa, Ehrenberg, 1872, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 320; 

 Abhandl. d. k. Akad. d. Wiss. Berlin, Taf. viii. fig. 15. 



Eadial proportion of the two shells = 2:1. Cortical shell thin waUed, spiny ; pores regular, 

 hexagonal, four times as broad as the bars. Six to eight pores on the half equator. Polar spines 

 conical, thin, scarcely as long as the radius of the cortical shell. 



Bimensions. — Diameter of the cortical shell 01, pores 0-002, bars 0-005 ; meduUary shell 005 ; 

 length of the polar spines 0-04, basal breadth 0-01. 



Habitat. — Philippine Sea, depth 3300 fathoms, Ehrenberg ; Station 206, depth 2100 fathoms. 



8. Stylosphcera euterpe, n. sp. 



Eadial proportion of the two shells = 3:l. Cortical shell thin walled, spiny ; pores regular, 

 circular, with hexagonal frames, twice as broad as the bars ; eight to ten on the half equator. Polar 

 spines conical, as thick as one pore at the base, about as long as the axis of the cortical shell. 



Dimensions. — Diameter of the cortical shell 0-12, pores 0-012, bars O'OOG ; medullary shell 0-0-4 ; 

 length of the polar .spines 0-1, basal breadth 0-012. 



Habitat. — South Pacific, Station 302, depth 1450 fathoms. 



9. StylosphcBra melpomene, n. sp. (PL 16, fig. 1). 



Eadial proportion of the two shells = 3:1. Cortical shell thin walled, spiny, with regular, circular 

 pores, four times as broad as the bars ; eight to ten on the half ecpator. Polar spines three-sided 

 prismatic, pointed, as broad as one pore, only one-third as long as the axis of the sphere (the two 

 shells connected by four thin beams, two opposite in the main axis, two in the equatorial axis). 



