EEPORT ON THE RADIOLARIA. 735 



Subgenus 1. Litholopharhim, Haeckel. 

 Definition. — Ten radial spines. 



1. Litholophus decimalis, n. sp. 



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

 their whole length. 



Dimensions. — Length of the spines 0'2 to 0"3, breadth 0"006. 



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



2. Litholophus pyramidalis, n. sjj. 



Ten radial spines, four-sided pyramidal, with prominent smooth edges, gi'adually thickened 

 from the small pyramidal base towards the truncated distal end. 



Dimensions. — Length of the spines 0'3 to 0"4, 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 0-008. 

 Habitat. — CosmopoHtau ; 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 chstal end. 



Di7nensions. — Length of the spines 0-2 to 0-3, breadth in the basal part 0-002, in the middle 

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



Habitat. — South Atlantic, Station 332, sui-face. 



Subgenus 2. Litholophidium, Haeckel. 



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

 commonly twelve to sixteen. 



