Habitat.—Central Pacific, Station 272, depth 2600 fathoms.
Subgenus 2. Clathrocorona, Haeckel, 1881, Prodromus, p. 431.
Definition.—Horn of the cephalis fenestrated. Peristome on the margin of the basal mouth with a corona of spines.
5. Clathrocanium diadema, n. sp. (Pl. [64], fig. 2).
Clathrocorona diadema, Haeckel, 1881, Prodromus, p. 431.
Cephalis hemispherical, thorny, with irregular roundish pores, and a large prismatic horn of twice the length, the three edges of which are denticulate and fenestrated, each with a series of square pores. Length of the two joints = 1 : 3, breadth = 2 : 4. Thorax thorny, with three broad fenestrated divergent ribs, which are separated by three large ovate holes (twice as long as the cephalis) and have their prominent distal ends connected below by a broad circular ring of lattice-work (with irregular polygonal small meshes). Peristome wide, two-thirds as broad as the thorax, with a circular corona of small square pores and alternating prominent small teeth.
Dimensions.—Cephalis 0.03 long, 0.04 broad; thorax 0.07 long, 0.09 broad.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
6. Clathrocanium reginæ, n. sp. (Pl. [64], fig. 4).
Clathrocorona reginæ, Haeckel, 1881, Prodromus, p. 431.