1. Lychnodictyum challengeri, Haeckel.
Dictyopodium challengeri, Wyville Thomson, 1877, Atlantic, vol. i. p. 234, fig. 52.
Dictyophimus (vel Tripocyrtis) challengeri, Haeckel, 1878, Protistenreich, p. 47, fig. 35.
Shell campanulate, smooth, with sharp collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical, with a large, oblique, pyramidal horn thrice the length. Thorax with three inflated bosoms between the three decurrent ribs, which are prolonged into three vertical, parallel, pyramidal, in the upper half fenestrated feet, as long as the thorax. Pores regular, circular. Mouth constricted, flat, half as broad as the thorax.
Dimensions.—Cephalis 0.03 diameter; thorax 0.08 long, 0.12 broad.
Habitat.—Tropical Atlantic, Station 338, depth 1990 fathoms.
2. Lychnodictyum wyvillei, n. sp.
Shell pyramidal, smooth, with obliterated collar stricture. Length of the two joints = 1 : 3, breadth = 1 : 5. Cephalis subspherical, with a large, straight, pyramidal horn of twice the length. Thorax nearly tetrahedral, inflated, with three rounded, decurrent ribs, which are prolonged into three widely divergent, angular, curved feet, about as long as the shell, with pyramidal fenestrated base. Pores regular, circular. Mouth constricted, flat, half as broad as the thorax.
Dimensions.—Cephalis 0.025 diameter; thorax 0.08 long, 0.12 broad.
Habitat.—Central Pacific, Stations 266 to 274, depth 2350 to 2925 fathoms.