Shell regular, pyramidal, with flat collar stricture. Relative length of the two joints = 1 : 4, breadth = 2 : 6. Cephalis hemispherical, with a stout pyramidal horn of the same length. Thorax triangular pyramidal, with three prominent ribs, which are prolonged into three slender pyramidal feet, half as long. Pores small and very numerous, subregular, circular.
Dimensions.—Cephalis 0.03 long, 0.05 broad; thorax 0.1 long, 0.15 broad.
Habitat.—Central Pacific, Station 266, depth 2750 fathoms.
6. Dictyophimus challengeri, Haeckel.
Dictyophimus challengeri, Haeckel, 1878, Protistenreich, p. 47, fig. 35.
Shell campanulate, with sharp collar stricture. Relative length of the joints = 1 : 3, breadth = 1 : 4. Cephalis subspherical, with a stout pyramidal horn of twice the length, and numerous 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.