1596 THE VOYAGE OF H.M.S. CHALLENGER. 



6. Orosphcera horrida, n. sp. (PL 106, fig. 2). 



Eadial spines club-shaped, very strong, straight, about as long as the diameter of the polyhedral 

 shell, ovate and smooth in the distal half, slenderly conical, and armed with recurved spines in the 

 proximal half ; their outer third is the thickest, and five times as broad as the smooth bars of the 

 coarse network. Meshes of the latter irregularly quadrangular. 



Dimensions. Diameter of the shell 1'2 to 1'6, length of the spines 1'2 to 2'0, breadth 0'2. 



Habitat. South Pacific, Station 291, depth 2250 fathoms. 



7. Orosphcera clavigera, n. sp. 



Eadial spines club-shaped, thickened towards the distal end, more or less curved, spinulate, 

 about as long as the diameter of the spherical shell ; in the distal third four to six times as broad 

 as the spinulate bars. Meshes irregularly polygonal, the majority pentagonal. 



Dimensions. Diameter of the shell 2'0 to 2'5, length of the spines 1'8 to 2'2, breadth 016. 



Habitat. Central Pacific, Station 263, depth 2650 fathoms. 



Subgenus 2. Orothamnus, Haeckel. 

 Definition. Radial spines branched or arborescent. 



8. Orosphcera ramigera, n. sp. 



Eadial spines cylindrical, spinulate, straight, about twice as long as the diameter of the 

 spherical shell and as thick as its spinulate bars. Numerous simple spinulate branches, straight or 

 slightly curved, and two to four times as long as the meshes, are irregularly scattered, and 

 arise nearly perpendicularly from the bars. 



Dimensions. Diameter of the shell 2'0 to 2'2, length of the spines 4 to 5, breadth 0'05. 



Habitat. South Atlantic, Station 332, depth 2200 fathoms. 



9. Orosphcera furcata, n. sp. 



Eadial spines cylindrical, smooth, irregularly curved, about as long as the radius of the 

 spherical shell and as thick as its smooth bars, forked at the distal end, with two or three terminal 

 branches of various lengths. Meshes irregularly polygonal (the majority hexagonal). 



Dimensions. Diameter of the shell T2, length of the spines 0'7, breadth 0'03. 



Habitat. Indian Ocean, Madagascar (Eabbe), surface (?). 



10. Orosphcera confluens, n. sp. 



Eadial spines cylindrical, smooth, irregularly curved, two to three times as long as the diameter 

 of the polyhedral shell, twice as broad as its smooth bars, bearing numerous irregular, lateral 



