Habitat.—Cosmopolitan; Atlantic, Pacific; many stations, surface.
Subgenus 2. Pterocanidium, Haeckel.
Definition.—Free basal edge of the abdomen between the three feet convex, forming three rounded or semicircular prominent lobes between them.
11. Pterocanium eucolpum, n. sp. (Pl. [73], fig. 4).
Dictyopodium eucolpum, Haeckel, 1881, Prodromus et Atlas.
Shell about triangular-prismatic, with two deep strictures, smooth. Length of the three joints = 1 : 3 : 3, breadth = 1 : 3 : 4. Cephalis subspherical, with a conical, oblique horn of the same length. Thorax inflated, with three hemispherical swellings between the three crests, and with subregular, hexagonal pores. Abdomen longer, with much smaller, irregular, roundish pores, forming three broad, convex lobes between the three feet. (In the figured specimen the lobes were not fully developed, and extremely thin below the line parallel to the edge. In another specimen, found afterwards in the same locality, the three lobes were much larger, semicircular, and reached almost to the basal plane of the ends of the feet by reason of their convexity.) Feet strong, with slightly convex back, divergent.
Dimensions.—Length of the three joints, a 0.03, b 0.09, c 0.1; breadth, a 0.03, b 0.09, c 0.12.
Habitat.—North Pacific, Station 244, depth 2900 fathoms.
12. Pterocanium bicorne, n. sp. (Pl. [73], fig. 5).
Dictyopodium bicorne, Haeckel, 1881, Prodromus et Atlas.