Ceratospyris setigera, Bütschli, 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 539, Taf. xxxii. figs. 11a, 11b.
Shell nut-shaped, tuberculate, with a complete internal sagittal ring and numerous small circular pores. Basal plate with four larger central and a circle of twelve to twenty smaller peripheral pores. Apical horn half as long as the shell, bristle-shaped. Three primary feet longer and more deeply inserted than the three secondary feet; all six feet strongly divergent, bristle-shaped, shorter than the shell.
Dimensions.—Shell 0.06 long, 0.09 broad; horn 0.03 long; primary feet 0.05, secondary 0.02 long.
Habitat.—Fossil in Barbados.
3. Hexaspyris bütschlii, Haeckel.
Ceratospyris triomma, Bütschli (non Ehrenberg), 1882, Zeitschr. f. wiss. Zool., vol. xxxvi. p. 539, Taf. xxxii. fig. 12, a, b.
Shell nut-shaped, spinulate, with a complete internal sagittal ring and subregular circular pores. Basal plate with twelve pores (four larger central and eight smaller peripheral). Apical horn stout, oblique, as long as the shell. Six feet of equal length, slightly divergent, nearly vertical, slender, three to four times as long as the shell.
Dimensions.—Shell 0.05 long, 0.07 broad; horn 0.06, feet 0.15 to 0.2 long.
Habitat.—Fossil in Barbados.
4. Hexaspyris spinosa, Haeckel.