Habitat.—Tropical Atlantic, Station 348, depth 2450 fathoms.
3. Clathrocircus decaporus, n. sp.
Sagittal ring ovate, thorny, with five pairs of pores (two apical and three basal). The four apical pores are roundish and form a cross. The six basal pores are triangular and form a hexagonal plate with thorny margin; the two jugular pores are somewhat larger than the two cervical, and half as broad as the two cardinal pores.
Dimensions.—Height of the sagittal ring 0.09, breadth 0.07.
Habitat.—North Pacific, Station 256, depth 2950 fathoms.
4. Clathrocircus stapedius, n. sp. (Pl. [92], fig. 8).
Sagittal ring ovate, smooth, with six pairs of pores (two apical and four basal). The four apical pores are of nearly equal size and form a quadrangular mitral plate with two large lateral horns. The eight basal pores are of very different size (the four central far larger than the two anterior and the two posterior), and form a hexagonal basal plate, also with two large lateral horns. The four branched lateral horns (two upper and two lower) form together an incomplete frontal ring.
Dimensions.—Height of the sagittal ring 0.1, breadth 0.08.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
5. Clathrocircus dictyospyris, n. sp. (Pl. [92], fig. 9).