REPORT ON THE RADIOLARIA. 353 



Dimensions. Length of the cortical shell 0'18, breadth O14 ; thickness of its wall 0'035 ; 

 diameter of the outer medullary shell 004, of the inner - 02. 

 Habitat. South Atlantic, Station 325, surface. 



6. Spongoliva daturina, n. sp. 



Cortical shell one and a half times as long as broad, armed with very numerous, thick and 

 short, conical radial spines, about as long as the outer medullary shell. Spongy framework 

 compact, with small meshes, its thickness equal to half the length of the outer ellipsoidal 

 medullary shell. 



Dimensions. Length of the cortical shell 0'24, breadth 0'16 ; thickness of its wall 0'025 ; 

 diameter of the outer medullary shell 0'045 to 0'035, of the inner 0'025. 



Habitat. Pacific, central area, Station 272, surface 



Genus 151. Spongoxiphus, 1 n. gen. 



Definition. S pongurida with spongy ellipsoidal cortical shell, enclosing a 

 double, spherical or ellipsoidal, latticed medullary shell. On the poles of the axis occur 

 two opposite strong spines. 



The genus Spongoxiphus differs from Spongoliva by the development of two strong 

 spines in the axis of the shell, on its two opposite poles. From the similar Sponga- 

 tractus it differs in the duplication of the medullary shell. It may also be regarded 

 as a Stylatractus, in which the simple latticed cortical shell is replaced by an irregular 

 spongy framework. 



1. Spongoxiphus splicer ococcus, n. sp. 



Cortical shell one and a half times as long as broad, with thorny surface. Spongy framework 

 compact, with small meshes, its thickness equal to the radius of the outer medullary shell. Both 

 medullary shells spherical, the outer three times as broad as the inner. Polar spines very stout, 

 conical, slightly sulcated, about half as long as the cortical shell, as broad at the base as the 

 outer medullary shell. (Differs from Spongatractus pachystylus almost only in the double medullary 

 shell.) 



Dimensions. Length of the cortical shell 018, breadth 0'12 ; thickness of the spongy wall 

 0-025 ; diameter of the outer medullary shell 0'05, of the inner 0'016. 



Habitat. Fossil in the rocks of Barbados (Haeckel) ; also living in the Pacific, central area, 

 Station 265, depth 2900 fathoms. 



1 Sponf/oxiphus = Spongy sword ; airoyyoc, t-i'po;. 

 (?OOL. CHALL. EXP. PART XL. 1885.) Rr 46 



