REPORT ON THE RADIOLARIA. 45 



Dimensions. — Diameter of the capsules 0'16 to 0-18, length of the spicula 0-1 to 0-2. 

 Habitat. — South Atlantic (Tristan da Cunha), Station 332, surface. 



Subgeuus 3. Sphcerozonura, Haeckel. 



Definition. — Spicula all geminate-radiate, but with a different and variable numljer 

 t>f shanks on eacli end of the middle rod. 



17. SphcBrozonm stellatum, n. sp. 



Spicula all geminate-radiate, with a strong middle rod and a variable number of shorter 

 radiating shanks on the two ends of it. Shanks straight, nearly conical, smooth ; for the most part 

 three or four shanks on each end, but sometimes also five or six ; very often this number is unequal 

 on the two ends. 



Dimensions. — Diameter of the central capsules O'l to 0"2, length of the spicula (>05 to 0'15. 



Habitat. — Central Pacific, Station 270, surface. 



18. Sphcerozoum geminatum, n. sp. (PL 4, fig. 4). 



Spicula all geminate-radiate, with a strong middle rod and a variable number of longer radiant 

 shanks on each end of it. Shanks straight, conical, in the distal half thorny ; commonly either 

 three or four shanks on each end of the middle rod, often also three on one end, four on the other 

 end ; rarely five or six rays on one end. 



Dimsnsions. — Diameter of the capsules 0'15 to 0-2, length of the spicula 0-05 to 0-1. 



Habitat. — Indian Ocean, Ceylon, Haeckel ; surface. 



19. Sphcerozoum circumtextum, n. sj). 



Spicula all geminate-radiate, with a very variable number of rays (two to six) on each end of 

 the thin middle rod. All spicula very thin and delicate, smooth, with curved or bent shanks, 

 densely covering the central capsule lilve a cobweb. The number of, rays on each end is usually 

 different, generally four or five, often also two or three, rarely sLx. 



Dimensions. — Diameter of the capsule O^l to 0'2, length of the spicula 01)4 to 0'12. 



Habitat. — Southeast part of the ImUan Ocean, Station 160, surface. 



20. SphcErozoum variabile, n. sp. (PL 4, fig. 5). 



Spicula all geminate-radiate, with a short middle rod and a variable number of shanks on each 

 end of it. Shanks four to eight times as long as the middle rod, curved or bent, in the distal half 

 thorny ; their number is commonly different on the two ends of it, three or five, often also four or 

 six, rarely two ; their size and form very variable. 



