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



6. Haliomma lirianihus, n. sp. (PL 28, figs. 1, la, 1/;). 



Cortical shell thick walled, three times as broad as the medullary shell, with regular, rosette- 

 shaped pores, twice as broad as the bars ; eight to ten on the radius. The regular structure of the 

 eleo'ant pores is the same as in the preceding species, but without prominent crested frames (fig. 

 Ih). Also the medullary shell (fig. Iff) is different, much thinner and smaller, with simple, circular 

 pores, which are three times as broad as the bars. The two shells are connected by numerous 

 (twenty ?) radial beams. 



Dimensions. — Diameter of the outer shell 015, of the inner O'Oo ; pores of the former O'Ol, of 

 the latter 0-005 ; length of the spines 0-005 to 0-02. 



Habitat. — Central Pacific, Station 271, depth 2425 fathoms. 



7. Haliomma castanea, Haeckel. 



Haliomma castanea, Haeckel, 1862, Monogr. d. Eadiol., p. 428, Taf. xxiv. tig. 4. 



Cortical shell thick walled, three times as broad as the meduUary shell ; pores of both regular,' 

 circular, twice as broad as the bars (seven to eight on the radius of the outer, four to five on the 

 racUus of the inner shell), the two connected by six to twelve (?) strong radial beams. Eadial spines 

 bristle-shaped, with conical bases, twice as long as the diameter of the cortical pores (one spine at 

 the nodal-point between every three pores). 



Dimensions. — Diameter of the outer shell 0-1 to 0-15, inner 0-03 to 0-05 ; pores of the former 

 0-005, of the latter 0-003 ; length of the spines 0-005 to 0-01. 



Habitat. — Cosmopolitan ; Mediterranean, Atlantic, Indian, Pacific, surface. 



8. Haliomma horridum, Stohr. 



Haliomma horridum, Stohr, 1880, Palseontogr., vol. xxvi. p. 87, Taf. i. fig. 10. 



Cortical shell thick walled, two and a half times as broad as the medullary shell. Pores regular, 

 circular, of the same breadth as the bars ; eight to ten on the radius. Eadial spines conical, stout, 

 nearly half as long as the radius. (Differs from the closely allied Haliomma castanea in the 

 smaller pores and larger spines.) 



Dimensions. — Diameter of the outer shell 0-14, of the inner 0-06 ; pores of the former 0-004, of 

 the latter 0-02. 



Habitat. — Fossil in Tertiary rocks of Barbados and Sicily; living in the Atlantic, Station 9, depth 

 3150 fathoms, and Station 353, depth 2965 fathoms. 



9. Haliomma datura, n. sp. 



Cortical shell thin walled, only one and a half times as broad as the medullary shell, both having 

 regular, circular pores, four to six times as broad as the bars (five to six on the radius of the outer, 

 three to four on the radius of the inner shell), the two connected by numerous (forty to sixty ?) thin, 

 short, radial beams. Eadial spines conical, twice as long as the diameter of one cortical pore, 

 arising from all the nodal-points between them. 



