17. Dictyophimus triserratus, n. sp. (Pl. 61, fig. 17).
Shell three-sided pyramidal, with slight collar stricture. Relative length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis small, subspherical, with a large pyramidal horn three times as long. Thorax with much larger, irregular roundish, double-edged pores, and three prominent, serrate ribs, which are prolonged into three pyramidal strongly divergent feet of the same length.
Dimensions.—Cephalis 0.02 long, 0.02 broad; thorax 0.06 long, 0.09 broad.
Habitat.—Central Pacific, Station 274, depth 2750 fathoms.
18. Dictyophimus bicornis, n. sp.
Shell thorny, with deep collar stricture. Relative length of the two joints = 2 : 3, breadth = 2 : 3. Cephalis nearly as large as the thorax, subglobular, with numerous small, circular pores, and two divergent pyramidal horns of half the length (a major occipital and a minor frontal horn). Thorax three-sided pyramidal, with larger irregular pores and three serrate ribs, which are prolonged into three prismatic spiny feet of half the length. (Differs from the similar Dictyophimus sphærocephalus, Pl. 57, fig. 10, mainly in the double horn and the spinulate feet.)
Dimensions.—Cephalis 0.05 long, 0.05 broad; thorax 0.08 long, 0.07 broad.
Habitat.—Western Tropical Pacific, Station 225, depth 4475 fathoms.
19. Dictyophimus pocillum, Ehrenberg.
Shell thorny, with distinct collar stricture. Relative length of the two joints = 1 : 5, breadth = 1 : 5. Cephalis nearly spherical, with numerous small conical spines. Thorax flat, three-sided pyramidal with large, irregular, roundish pores, and three strong, widely divergent, spinulate ribs, which are prolonged into three prismatic spinulate feet of the same length.
Dimensions.—Cephalis 0.03 long, 0.03 broad; thorax 0.15 long, 0.15 broad.
Habitat.—Fossil in Barbados.
20. Dictyophimus cienkowskii, n. sp. (Pl. 60, fig. 1).
Shell spiny, flatly pyramidal, with slight collar stricture. Relative length of the two joints = 1 : 3, breadth = 2 : 6. Cephalis flat, cap-shaped, three times as long as broad, with numerous bristle-shaped spines three times as long. Thorax also spiny, with irregular, very large, polygonal meshes and thin bars; its three ribs prolonged into three very long and thin, widely divergent, prismatic feet, bearing numerous long spines on the three edges.
Dimensions.—Cephalis 0.025 long, 0.05 broad; thorax 0.075 long, 0.15 broad.
Habitat.—North Pacific, Station 250, surface.
