1076 THE VOYAGE OF H.M.S. CHALLENGER. 



Dimensions. Shell 0'07 long, 0'08 broad. 



Habitat. Central Pacific, Stations 271 to 274, depth 2350 to 2750 fathoms ; also fossil in 

 Barbados. 



11. Dictyospyris mammillaris, n. sp. (PI. 89, figs. 9, 10). 



Shell mammillate, nut-shaped, with deep sagittal stricture. Mammilla? of the surface hemi- 

 spherical, with a conical apex. Pores not numerous, large, roundish. Two pairs of large pores on 

 each side of the ring. Basal plate with four large pores. 



Dimensions. Shell 0'06 long, 0'08 broad. 



Habitat. Western Tropical Pacific, Station 225, depth 4475 fathoms. 



12. Dictyospyris anthophora, n. sp. (PI. 89, fig. 8). 



Shell tuberculate, nut-shaped, nearly cubical, without external' sagittal strictures. Pores not 

 numerous, large, polygonally roundish. Bars between them compressed, elevated, with large, cam- 

 panulate or flower-like tubercles on the nodal points. Basal plate with four large pores. 



Dimensions. Shell 0'07 long, 0'09 broad. 



Habitat. North Atlantic, Station 349, depth 2450 fathoms. 



13. Dictyospyris quadriloba, n. sp. 



Shell nut-shaped, smooth, with deep sagittal stricture. Pores numerous, small, circular, on 

 each side of the ring three to four times as large as on the lateral sides. Basal plate with four 

 very large collar pores and a circle of twenty to twenty-five very small peripheral pores. 



Dimensions. Shell 0'08 long, Oil broad. 



Habitat. Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms. 



14. Dictyospyris messanensis, J. Midller. 



Dictyospyris messanensis, J. Miiller, 1858, Abhancll. d. k. Akad. d. Wiss. Berlin, p. 46, Taf. ii. 



fig. 8. 

 Dictyospyris messanensis, Haeckel, 1862, Monogr. d. Kadiol., p. 291. 



Shell nut-shaped, spinulate, with deep sagittal stricture. Pores numerous and small, irregular 

 roundish. No larger annular pores on the sides of the ring. Basal plate with four large, nearly 

 equal, pear-shaped collar pores. 



Dimensions. Shell 0'06 long, 0'08 broad. 



Habitat. Mediterranean ; Messina, surface. 



Subgenus 4. Dictyospyromma, Haeekel. 

 Definition. Basal plate with six or more collar pores. 



