conical, straight wings, of half the length, opposite in pairs in two meridional planes, perpendicular to one another (compare Tetralacorys, Pl. 65, figs. 4, 5).
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.1 long, 0.09 broad.
Habitat.—South Pacific, Station 300, depth 1375 fathoms.
2. Sethophæna hexaptera, n. sp. (Pl. 97, fig. 13).
Shell rough, pear-shaped, with distinct collar stricture. Length of the two joints = 1 : 4, breadth = 2 : 4. Cephalis hemispherical, with a conical horn of the same length. Thorax inflate, inversely ovate, nearly pear-shaped, with subregular, circular pores. From its upper half arise, by a broad base, six divergent, strong, conical wings, which are horn-like, curved downwards, and half as long as the thorax.
Dimensions.—Cephalis 0.025 long, 0.04 broad; thorax 0.09 long, 0.08 broad.
Habitat.—Central Pacific, Station 268, depth 2900 fathoms.
3. Sethophæna enneaptera, n. sp.
Shell rough, with sharp collar stricture. Length of the two joints = 1 : 6, breadth = 1 : 3. Cephalis subspherical, with a stout conical horn of twice the length. Thorax inversely ovate, with pointed, conical, basal part, and irregular, roundish pores. From its middle part arise, by a broad triangular base, nine compressed, divergent wings, which are a little curved, slender, and about as long as the thorax.
Dimensions.—Cephalis 0.025 long, 0.03 broad; thorax 0.17 long, 0.1 broad.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
4. Sethophæna polyptera, n. sp.
Shell thorny, with slight collar stricture. Length of the two joints = 1 : 10, breadth = 3 : 8. Cephalis flat, cap-shaped, without horn. Thorax pear-shaped, with hemispherical base and regular, circular pores. From its lower half (beyond the equator) arises a corona of numerous short conical wings (eighteen to twenty-four), which are a little curved, and divergent downwards, scarcely one-third as long as the thorax.
Dimensions.—Cephalis 0.015 long, 0.04 broad; thorax 0.15 long, 0.12 broad.
Habitat.—North Pacific, Station 253, depth 3125 fathoms.
Genus 571. Clistophæna,[1] Haeckel, 1881, Prodromus, p. 433.
Definition.—Sethophænida (vel Dicyrtida multiradiata clausa) with terminal apophyses. Cephalis with a horn.
- ↑ Clistophæna = Closed shell; κλειστός, φαῖνα.
