Cortical shell thorny, transverse-elliptical. Lateral girdle very broad, one and a third times as broad as long. Transverse girdle also very broad, with five pores on the isthmus. Sagittal septum shorter than the elliptical medullary shell. Eight gates small, roundish.
Dimensions.—Length of the medullary shell 0.05, breadth 0.04; length of the cortical shell 0.11, breadth 0.15.
Habitat.—Western Tropical Pacific, Station 224, depth 1850 fathoms.
Subgenus 2. Octopylura, Haeckel.
Definition.—Cortical shell armed with large, symmetrically disposed spines.
5. Octopyle amphistyle, n. sp.
Cortical shell smooth, nearly spindle-shaped, about twice as long as broad. Transverse girdle broad, with four large pores on the isthmus. Lateral girdle lanceolate. Sagittal septa about as long as the medullary shell, prolonged at both poles of the principal axis into two opposite, strong, angular spines. Eight gates obliquely quadrangular.
Dimensions.—Length of the medullary shell 0.07, breadth 0.05; length of the cortical shell 0.2, breadth 0.12.
Habitat.—Pacific, central area, Station 272, depth 2600 fathoms.
6. Octopyle staurostyle, n. sp.