REPORT ON THE RADIOLARIA. 1251 



4. Sethamphora mongolfieri, Haeckel. 



Eucyrtidium mongnljieri, Ehrenberg, 1854, Mikrogeol., Taf. xxxiv. fig. 18; Abhandl. d. k. 

 Akad. d. Wiss. Berlin, 1S75, p. 72, Taf. x. fig. 3. 



Shell urceolate, smooth, with distinct collar stricture. Length of the two joints = 2 : 9, breadth 

 = 3:7. Cephalis campanulate, with eighteen ribs and small pores. Thorax nearly ellipsoidal, witli 

 eighteen prominent ribs, and eighteen longitudinal rows of regular circular pores between them 

 (eight pores in each row ; therefore 144 pores altogether). Mouth constricted, only one-third as broad 

 as the thorax. 



Dimeiisions. — Cephalis 0-02 long, 0"03 broad ; thorax b'09 long, 0-07 broad. 



Habitat. — Fossil in Rarbados. 



5. Sethamphora costata, n. sp. 



Shell urceolate, smooth, very similar to the preceding species ; also with eighteen longitudinal 

 ribs, but differing in the larger size of the cephalis and its pores, and in the more slender and ovate 

 form of the thorax. Length of the two joints = 5 : 10, breadth = 5:8. Pores of the cephalis more 

 numerous. Mouth half as broad as the thorax. 



Di7nensio7is. — Cephalis 0'05 long, O'Oo broad ; thorax 01 long, 0'08 broad. 



Halitat. — Central Pacific, Stations 265 to 274, depth 2350 to 2925 fathoms. 



6. Sethamphora serrata, n. sp. 



Shell ovate, spinulate, without external collar stricture. Length of the two joints = 1:6, 

 breadth = 2:4. Cephalis flat, cap-shaped, with small circular pores. Thorax ovate, truncate, 

 with eighteen seiTate longitudinal ribs, alternating with eighteen longitudinal rows of short and 

 broad rather oblong pores (twenty to thirty pores in each row). Mouth strongly constricted, only 

 one-fourth as broad as the thoi'ax. 



Dimensions. — Cephalis 0'02 long, 0-04 bi'oad ; thorax 0-12 long, 0-08 broad. 



Habitat. — Tropical Atlantic, Station 348, depth 2450 fathoms. 



7. Sethamphora ojnpulla, Haeckel. 



Eucyrtidium ampulla, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 15; Ahliandl. d. k. Akad. 

 "d. Wiss. BerhD, 1875, p. 72, Taf. x. figs. 11, 12. 



Shell broad, urceolate, spiny, with sharp coUar stricture. Length of the two joints = 1:4, 

 breadth = 1:5. Cephalis subspherical, with few small pores (in figs. 12a and 12& of Ehrenberg, loc. cit., 

 broken off, so that the four pores of the cortinar septum appear). Thorax inflated, bottle-shaped, with 

 twenty prominent, sharply dentate ribs, alternating with twenty longitudinal rows of circular pores 

 (about eight pores in each row). Mouth flat, constricted, one-third as broad as the thorax. 



Dimensions. — CephaHs 0025 long, 003 broad ; thorax 0"1 long, 044 broad. 



Habitat. — Fossil in Barbados. 



