Shell smooth, campanulate, with three deep strictures. Four joints of different lengths; the fourth joint is the broadest, twice as long as the third and the second, three times as long as the hemispherical cephalis, which bears a stout, pyramidal, oblique horn of twice the length. Mouth little constricted. Pores regular, circular, in transverse rows, three rows in each of the three first joints, five or six rows in the last joint.
Dimensions.—Length of the shell (with four joints) 0.12; length of the fourth joint 0.05, breadth 0.07.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.
15. Eucyrtidium galea, Haeckel.
Eucyrtidium galea, Haeckel, 1862, Monogr. d. Radiol., p. 324, Taf. vii. figs. 8-10.
Lithocampe galea, Haeckel, 1860, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 838.
Shell smooth, helmet-shaped, with four sharp strictures. Five joints of different lengths. Cephalis small, spherical, with a thin pyramidal horn of the same length. Second joint conical, about as long as the third, longer than the fourth and the fifth joints. The third joint is the broadest. Pores regular, circular, small and numerous.
Dimensions.—Length of the shell (with five joints) 0.18; length of the second and the third joints 0.05, of the fourth 0.03; breadth 0.08 to 0.1.
Habitat.—Mediterranean (Messina), surface.
16. Eucyrtidium eruca, Ehrenberg.