REPORT ON THE RADIOLARIA. 735 



Subgenus 1. Litholopharium, Haeckel. 

 Definition. Ten radial spines. 



1. Litholophus decimalis, n. sp. 



Ten radial spines, four-sided prismatic, with prominent smooth edges, of equal breadth throughout 

 their whole length. 



Dimensions. Length of the spines - 2 to - 3, breadth 0006. 



Habitat. Cosmopolitan; Mediterranean, Atlantic, Indian, Pacific, surface. 



2. Litholophus pyramidalis, n. sp. 



Ten radial spines, four-sided pyramidal, with prominent smooth edges, gradually thickened 

 from the small pyramidal base towards the truncated distal end. 



Dimensions. Length of the spines 0'3 to 04, breadth in the basal part 0'002, in the middle 

 part 0-006, in the distal part 0'012 to 0'02. 



Habitat. Central Pacific, Station 266, surface. 



3. Litholophus decapristis, n. sp. (PL 129, fig. 2). 



Ten radial spines, four-sided prismatic, with prominent, elegantly denticulated edges, of equal 

 breadth in their whole length. 



Dimensions. Length of the spines 0'2 to 0'4, breadth O'OOS. 

 Habitat. Cosmopolitan ; Mediterranean, Atlantic, Pacific, surface. 



4. Litholophus decastylus, n. sp. 



Ten radial spines, four-winged pyramidal, with broad and thin, elegantly denticulated edges, 

 gradually thickened from the small pyramidal base towards the truncated distal end. 



Dimensions. Length of the spines 0'2 to 0'3, breadth in the basal part - 002, in the middle 

 part 0-005, in the distal part 0'015. 



Habitat. South Atlantic, Station 332, surface. 



Subgenus 2. Litholophidium, Haeckel. 



Definition. Number of the radial spines variable, between ten and twenty, 

 commonly twelve to sixteen. 



