Dimensions.—Height of the sagittal ring 0.14 to 0.18, breadth 0.1 to 0.12.
Habitat.—Cosmopolitan; Atlantic, Indian, Pacific, at various depths.
Genus 412. Stephaniscus,[[31]] n. gen.
Definition.—Semantida with four typical basal feet (two sagittal and two lateral or pectoral feet).
The genus Stephaniscus differs from the preceding Cortiniscus in the production of a fourth (sternal) foot, and therefore exhibits the same relation to it that Stephanium among the Stephanida bears to Cortina. It differs from Stephanium, in the production of a basal ring, with pores or gates between the bases of the basal feet. Two of these feet are sagittal (the posterior caudal and the anterior sternal foot), whilst the other two are lateral or pectoral (right and left). The basal lattice-plate exhibits either two pores ("jugular gates") or four pores (two anterior jugular and two posterior cardinal gates).
1. Stephaniscus tetrapodius, n. sp.
Sagittal ring nearly circular, smooth, with a short conical apical horn. Basal ring square, smooth, with two triangular gates. Four feet simple, equal, conical, divergent, about as long as the diameter of the ring.
Dimensions.—Height of the sagittal ring 0.08, breadth 0.07.
Habitat.—Central Pacific, Stations 270 to 274, depth 2350 to 2925 fathoms.
2. Stephaniscus quadrifurcus, n. sp. (Pl. [92], fig. 14).