very small pores. Thorax nearly hemispherical, with three vaulted bosoms between the three decurrent ribs, which are prolonged into three nearly parallel and vertical feet of about the same length. Pores subregular, circular, of medium size. This species is very similar to Lychnodictyum challengeri, Haeckel, but differs in the smaller straight horn and the longer solid feet, which are not fenestrated.
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.09 long, 0.13 broad.
Habitat.—Tropical Atlantic, Station 347, surface.
7. Dictyophimus lasanum, n. sp. (Pl. 61, fig. 5).
Shell nearly pear-shaped, with distinct collar stricture. Relative length of the two joints = 1 : 3, breadth = 1 : 3. Cephalis hemispherical, with a conical horn of the same length. Thorax nearly spherical, on both poles truncate and constricted, with three decurrent curved ribs and small regular circular pores. The prolongations of the ribs form three divergent pyramidal straight feet, nearly as long as the thorax.
Dimensions.—Cephalis 0.02 long, 0.03 broad; thorax 0.09 long, 0.09 broad.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
8. Dictyophimus longipes, n. sp. (Pl. 61, fig. 3).
Shell three-sided pyramidal, with distinct collar stricture. Relative length of the two joints = 1 : 4, breadth = 2 : 6. Cephalis hemispherical, with a rudimentary pyramidal horn, scarcely one-fourth as long; and with small circular regular pores. Thorax with larger irregular pores, and three vaulted bosoms between the three decurrent ribs, which are prolonged into three very long and slender prismatic feet, S-shaped, curved, and twice to three times as long as the shell.
Dimensions.—Cephalis 0.02 long, 0.04 broad; thorax 0.09 long, 0.13 broad.
Habitat.—South Pacific, Station 300, depth 1375 fathoms.
9. Dictyophimus gracilipes, Bailey.
Shell three-sided pyramidal, with a deep collar stricture. Relative length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis hemispherical, with a thin horn of the same length. Thorax with three curved ribs, which are prolonged into three divergent angular feet of the same length. Pores irregular roundish.
Dimensions.—Cephalis 0.02 long, 0.03 broad; thorax 0.05 long, 0.08 broad.
Habitat.—North Pacific, Station 240, surface, Kamtschatka (Bailey).
10. Dictyophimus cortina, n. sp. (Pl. 61, fig. 1).
Shell three-sided pyramidal, with distinct collar stricture. Relative length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical, with a pyramidal horn of half the length. Thorax
