EEPORT ON THE RADIOLARIA. 1685 



3. Castanidium buchanani, n. sp. (PL 113^ fig. 7). 



Pores regular, circular, without frames, twice as broad as the bars, of variable size. Bristles 

 five to six times as long as one pore. Eadial maia-spines numerous, straight, slender, cylindrical, 

 about as long as the diameter of the shell. 



Dimensions. — Diameter of the shell 0-25 to O'S, of the pores 0-012 to 0-02. 



Habitat. — Tropical Atlantic, Stations 34:6 to 349, surface. 



4. Castanidium mv.rrayi, u. sp. (PI. 113, figs. 5, 5o). 



Pores subregular, circular, without frames, three times as broad as the bars. Bristles three 

 times as long as one pore. Radial main-spines cylindrical, stout, irregularly curved, longer than 

 the shell-diameter, covered with longish hexagonal dimples, which are separated by a network of 

 prominent crests (fig. oa). 



Dimensions. — Diameter of the shell 0-4 to O^o, of the pores 0'02 to 0'025. 



Habitat. — North Atlantic, Station 352 to 354, surface. 



5. Castanidium aldrichi, n. sp. 



Pores subregular, circular, without frames, of variable size, about as broad as the bars. Bristles 

 four times as long as one pore. Eadial main-spines conico-cylindrical, irregularly curved, straight, 

 about as long as the radius. (The conical base of the spines is inflated and fenestrated, therefore 

 the shell is nearly polyhedral.) 



Dimensions. — ^Diameter of the shell 0-35 to 04, of the pores 012 to 0-015. 



Habitat. — Central Pacific, Stations 270 to 274, surface. 



6. Castanidium hromleyi, n. sp. 



Pores irregular, roundish, two to four times as broad as the bars. Bristles half as long as the 

 radius. Eadial main-spines cyliiidrical, straight, slender, longer than the shell- diameter. 

 Dimensions. — Diameter of the shell 0-22 to 0-26, of the pores 0-006 to 0-02. 

 Habitat. — Indian Ocean and Southern Pacific, Stations 162 to 169, surface. 



7. Castanidium hethelli, n. sp. 



Pores irregular, roundish or polygonal, two to three times as broad as the bars. Bristles one- 

 third as long as the radius. Eadial main-spines conico-cylindrical, irregularly curved, with dimpled 

 surface, somewhat longer than the radius. 



Dimensions. — Diameter of the sheU 0-5 to 0-6, of the pores 0-015 to 0-03. 



Habitat. — North Pacific, Stations 235 to 245, surface. 



