Eucyrtidium sipho, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 72, Taf. ix. fig. 2.

Shell with four joints, thick-walled, smooth. Cephalis subspherical, hyaline, without pores, with a thick, conical horn of twice the length. Thorax hemispherical. Third joint ovate, four times as long as the thorax, and of the same length as the thin, cylindrical fourth joint. Pores subregular, circular, in the fourth joint twice as broad as in the third, and three times as broad as in the second joint.

Dimensions.—Length of the shell (with four joints) 0.22. Length of the single joints, a 0.02, b 0.02, c 0.09, d 0.09; breadth 0.08.

Habitat.—Fossil in Barbados.

6. Eusyringium fistuligerum, Haeckel.

Eucyrtidium fistuligerum, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 70, Taf ix. fig. 3.

Shell with four joints, thin-walled, smooth. Cephalis subspherical, with numerous very small pores, and a stout, pyramidal horn of the same length. Thorax hemispherical. Third joint subspherical, four times as long as the thorax, and of the same length as the slender, inversely conical or cylindrical, fourth joint. Pores irregular, roundish or circular, in the fourth joint twice as broad as in the two preceding joints.

Dimensions.—Length of the shell (with four joints) 0.2. Length of the single joints, a 0.02, b 0.02, c 0.08, d 0.08; breadth 0.09.

Habitat.—Fossil in Barbados.

Subgenus 2. Eusyringoma, Haeckel.