Habitat.—South Pacific, Station 295, depth 1500 fathoms.
Subfamily 2. Theophænida, Haeckel, 1881, Prodromus, p. 437.
Definition.—Phormocyrtida with the basal mouth of the shell fenestrated (vel Tricyrtida multiradiata clausa).
Genus 609. Hexalatractus,[[226]] n. gen.
Definition.—Theophænida (vel Tricyrtida multiradiata clausa) with six lateral wings on the abdomen.
The genus Hexalatractus, and the following genus Theophæna, represent together the small subfamily Theophænida, or those Tricyrtida in which the terminal mouth of the shell is closed by lattice-work, and six or nine lateral apophyses indicate a multiradiate structure. The shell is more or less ovate or spindle-shaped, tapering towards both poles, and resembles greatly the triradiate Rhopalocanium. It may be derived from the latter by interpolation of three secondary or interradial wings between the three primary or perradial apophyses.
1. Hexalatractus sexalatus, n. sp.
Shell ovate, smooth, with two distinct strictures, length of the three joints = 3 : 6 : 9, breadth = 4 : 9 : 8. Cephalis subspherical, with a pyramidal horn of twice the length. Thorax campanulate; abdomen inversely conical; both with subregular, circular pores. Six divergent wings arise, beginning from the collar stricture, from the upper half of the shell, with broad triangular base; they are little curved downwards, with the convexity outside, and gradually tapering towards the distal end; the latter lies in the same horizontal plane as the basal apex of the abdomen.
Dimensions.—Length of the three joints, a 0.03, b 0.06, c 0.09; breadth, a 0.04, b 0.09, c 0.08.
Habitat.—Central Pacific, Stations 263, depth 2650 fathoms.