736 THE VOYAGE OF H.M.S. CHALLENGEE. 



5. Litholophus ligti7'inus, Haeckel. 



Litholophtis ligiirinus, Haeckel, 1865, Zeitschr. f. wiss. Zool., Bd. xv. p. 366. 



Spines of variable number, from eleven to twenty, commonly twelve to sixteen, four-sided 

 prismatic, with smooth thin edges, of equal breadth in their whole length or a little thinner 

 towards the proximal end. 



Dimensions. — Length of the spines 0"3, breadtli O'OOo. 



Habitat. — Mediterranean (Nice) ; Central Pacific, Station 274, surface. 



6. Litholophus rhipidmm, Haeckel. 



Litholophus rhipidltim, Haeckel, 1862, Monogr. d. Radiol., p. 402, Taf. xix. fig. 6. 



Spines of variable number, from eleven to twenty, commonly twelve to sixteen, four-sided 

 prismatic, with distantly denticulated edges, of equal breadth in their whole length or a little 

 tliinner towards both ends. 



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



Habitat. — Mediterranean (Messina) ; North Atlantic, Station 352, surface. 



Subgenus 3. Litholophonium, Haeckel. 

 Definition. — Number of the radial spines twenty (or more ?). 



7. Litholophus fasciculus, u. sj^. 



Spines constantly (?) twenty, four-sided prismatic, with smooth prominent edges, nearly of 

 equal breadth throughout their whole length. 



Dimensions. — Length of the spines 0'3 to O'o, breadth 0"008. 

 Habitat. — South Pacific, Station 291, surface. 



8. Litholophus penicillus, n. sp. 



Spines constantly twenty (or more ?), four-sided prismatic, with distantly denticulated edges, 

 gradually thickened from the small pyramidal base to the middle part, of equal breadth in the 

 distal half. 



Dimensions. — Length of the spines 0'3 to 0-4, breadth O'OOo to O'OOV. 



Habitat. — North Pacific, Statian 252, surface. 



Family XXXV. Chia stolid a, Haeckel. 



Acanthochiasmida, Haeckel, 1862, Monogr. d. Eadiol., p. 402. 

 Definition. — Acantharia with a variable number of simple radial spines, which are 

 grown together in pairs (two opposite spines of each pair representing together a 

 single diametral spine). Diametral spines crossed loosely in the centre of the spherical 

 or irregular roundish central capsule. No lattice-shell. 



