Shell smooth, flat, three-sided pyramidal, with deep collar stricture, very similar to the preceding species. Relative length of the two joints = 1 : 3, breadth = 2 : 7. Cephalis hemispherical, with a slender conical horn of twice the length. Thorax flatly vaulted, with irregular polygonal pores and thin bars; and with three widely divergent ribs, which are prolonged into three slender prismatic feet of thrice the length. In fig. 6 the shell is seen from the base and exhibits very distinctly the collar septum with its four large meshes, two minor jugular and two major cardinal pores. _Dimensions._--Cephalis 0.03 long, 0.07 broad; thorax 0.08 long, 0.2 broad. _Habitat._--North Pacific, Station 236, surface. {1199}14. _Dictyophimus lucerna_, Haeckel. _Lychnocanium lucerna_, Ehrenberg, 1854, Mikrogeol., Taf. xxxvi. fig. 6; Abhandl. d. k. Akad. d. Wiss. Berlin, 1875, p. 80, Taf. viii. fig. 3. _Lychnocanium lucerna_, Haeckel, 1862, Monogr. d. Radiol., p. 311. Shell smooth, three-sided pyramidal, with slight collar stricture. Relative length of the two joints = 1 : 4, breadth = 1 : 4. Cephalis hemispherical, with a thick conical horn of twice the length. Thorax with small regular, circular pores and three flat sides; between these arise three rounded ribs, which are prolonged into three short, conical, divergent feet, one-third as long as the thorax. _Dimensions._--Cephalis 0.02 long, 0.025 broad; thorax 0.08 long, 0.08 broad. _Habitat._--Fossil in Barbados. 15. _Dictyophimus hamosus_, Haeckel. _Lychnocanium hamosum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 78, Taf. vii. fig. 9. Shell pear-shaped, rough, with deep collar stricture. Relative length of the two joints = 1 : 2, breadth = 1 : 3. Cephalis subglobular, with a conical horn of twice the length. Thorax with small, regular, circular pores, and with three prominent ribs, prolonged into three vertical prismatic feet, which are about as long as the shell, parallel or a little convergent towards the distal end, with recurved teeth or hooks at the lateral edges. _Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.04 long, 0.06 broad. _Habitat._--Fossil in Barbados. 16. _Dictyophimus tridentatus_, Haeckel. _Lychnocanium tridentatum_, Ehrenberg, 1875, Abhandl. d. k. Akad. d. Wiss. Berlin, p. 80, Taf. vii. fig. 4. Shell smooth, three-sided pyramidal, with deep collar stricture. Relative length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical, with a conical horn of the same length, and some small accessory thorns. Thorax tetrahedral, with three smooth hyaline walls, bearing only a single series of small pores on each side of the three prominent ribs, which are prolonged into three strong prismatic curved feet of twice the length, with the convexity external. A group of small pores and a strong triangular tooth at the base of each foot. _Dimensions._--Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.08 broad.