REPORT ON THE RADIOLARIA. 331 



Subgenus 4. Stylatractium, Haeckel. 



Definition. Network of the outer shell irregular, with meshes of different size and 

 form ; surface thorny or papillose, covered with small spinules or tubercles. 



8. Stylatractus papillosus, n. sp. 



Cortical shell thin walled, with papillose surface, and irregular, simple, roundish pores, ten to 

 sixteen on the half equator, twice to three times as broad as the bars. Conical papillre of the 

 surface irregularly scattered. Polar spines conical, about as long as the main axis, at the base half 

 as broad as the inner medullary shell. 



Dimensions. Major axis 0'12, minor O'l ; pores - 006 to O'Ol, bars 0'003 ; main axes of the 

 medullary shells - 09 and 0'06 ; length of the polar spines 0'13, basal breadth O04. 



Habitat. Indian Ocean, surface (between Socotra and Ceylon), Haeckel. 



9. Stylatractus disetanius, n. sp. 



Cortical shell thin walled, with spiny surface, and irregular, roundish pores, eight to ten on the 

 half equator, twice to three times as broad as the bars. Every pore is divided by thinner bars into 

 four to six small roundish porules. Polar spines three-sided pyramidal, nearly as long as the main 

 axis, as broad at the base as the inner medullary shell. (Eesembles Xiphatractus glyptodon, PI. 17, 

 figs. 9, 10, but differs from it by the irregular network and the equal size of both polar spines.) 



Dimensions. Major axis 0'14, minor O'l ; pores 0'02, bars O'OOS, porules 0'007 ; main axes of 

 the two medullary shells - 08 and - 05 ; length of the polar spines 013, basal breadth 0'04. 



Habitat. South Pacific, near New Zealand, Station 169, surface. 



Genus 140. Xiphatractus, 1 n. gen. 



Definition. D ruppulida with a simple ellipsoidal cortical shell and double 

 medullary shell, in the main axis with two large opposite polar spines of different size 

 or form. 



The genus Xiphatractiis differs from the nearly related Stylatractus in the differ- 

 entiation of two polar spines (in the same manner as Druppatractus differs from Litha- 

 tractus). From the spherical Amphistylus it differs in the ellipsoidal form of the 

 cortical shell. 



Subgenus 1. Xiphatractara, Haeckel. 



Definition. Network of the cortical shell regular or subregular, with meshes of 

 nearly equal size and similar form ; surface smooth, without thorns or papillae. 



1 Xiphatractus = Sword-spindle ; J/^of dTpax.ro;. 



