REPORT ON THE RADIOLARIA. 1293 



10. SetJioconus Jiassa, Haeckel. 



Eucyrtidium nassa, Ehrenberg, 1875, Abhandl. d. k. Akad. d. "Wiss. Berlin, p. 72, Taf. ix. fig. 9. 



Cephalis slenderly ovate, with sharp collar stricture, few scattered pores, and a very stout, pyra- 

 midal horn of the same length, which is surrounded at the base by three short, divergent, ascending 

 spines (perhaps the remnants of the three cortinar rods of Eucccry]3halas, &c.?). Thorax slender, 

 conical, with straight outlines, and small, dense, regular, circular pores of equal size. 



JDimensions. — Cephalis 0'04 long, 002 broad ; thorax 012 long, 0"08 broad. 



Habitat. — Fossil in Barbados. 



11. Sethocoiius tahulatus, Ilaeckel. 



Cydadopltova tahulata, Ehrenberg, 1872, AbhanJl. d. k. Akad. d. "Wiss. Berlin, p. 289, 



Taf. iv. Cg. 18. 



Cephalis subspherical, with slight collar stricture, and numerous small, irregular pores, without 

 horn, or with a small conical horn. Thorax slenderly conical, with straight outlines, and large, 

 regular, hexagonal pores. Mouth truncate. (In the specimen 1 examined the thorax was longer 

 and more conically dilated ; the cephalis had a distinct small horn.) 



Dimensions. — Cephalis 0'02 long, 0'03 broad ; thorax 0"08 long, G-06 broad. 



Habitat. — North Atlantic, Antilles, depth IGOO fathoms (Ehrenberg); Station 347, depth 2250 

 fathoms. 



Subgenus 2. CornutelUum (vel Ceratarachnium), Haeckel, 1881, Prodromus, p. 4.30. 



Definition. — Cephalis very small, rudimentary, hyaline, vi^ithout distinct collar 

 septum, and without jjores (or with scarce, rudimentary pores). Thorax smooth. 



12. Sethoconus hexagonalis, Haeckel. 



Comutella trochns, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Derliu, p. 287, Taf. ix. fig. 14. 



Cephalis very small, subspherical, hyaline, without pores, with a rudimentary horn of half the 

 length. Thorax slenderly conical, or bottle-shaped, twice to three times as long as liroad ; in the 

 lower half nearly cylindrical, with very thin, thread-like bars, and regular, hexagonal pores, 

 increasing in size towards the mouth. 



Biviunsions. — Cephalis 0'005 diameter, thorax 012 long, 0'05 broad. 



Habitat. — Indian Ocean, Zanzibar, depth 2200 fathoms (PuUen). 



13. Sethoconus verrucosus, Haeckel 



Comutella verrucosa, Ehrenberg, If 

 fig. 16. 



Cephalis very small, subspherical, hyaline, without pores, with a rudnuentary liorn of half the 



Comutella verrucosa, Ehrenberg, 1872, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 287, Taf. is. 

 fis. 16. 



