a coronal of six strong ascending spines. Peristome beyond the stricture of the mouth somewhat dilated, with nine triangular, divergent teeth (broken off in the specimen figured).
Dimensions.—Length of the shell (with four joints) 0.18, breadth 0.09. Length of the single joints, a 0.02, b 0.04, c 0.04, d 0.08.
Habitat.—Western Tropical Pacific, Station 224, depth 1850 fathoms.
4. Cyrtophormis aculeata, n. sp.
Shell spiny, slenderly ovate, with five distinct strictures, each with a girdle of spines. The three middle joints are of nearly equal length, each half as long as the second, and one-third as long as the sixth joint. The fifth joint is the broadest, twice as broad as the constricted mouth. Pores regular, circular. Cephalis conical, with a bunch of strong, divergent spines. Peristome with nine strong, conical, vertical, parallel teeth.
Dimensions.—Length of the shell (with six joints) 0.18, breadth 0.08. Length of the first joint 0.02, the second 0.04, the three following 0.02, the sixth 0.06.
Habitat.—North Pacific, Station 241, depth 2300 fathoms.
5. Cyrtophormis acutata, Haeckel.
Shell rough, spindle-shaped, with six annular strictures. The third, fourth, and seventh joints are equal in length, three times as long as the first and the fifth joints. The fourth joint is the broadest, four times as broad as the constricted mouth. Pores irregular, roundish. Cephalis small, subspherical, with a short conical horn. Peristome with nine (?) irregular, triangular, little convergent teeth.
Dimensions.—Length of the shell (with seven joints) 0.22, breadth 0.11. Length of the third, fourth, and seventh joints 0.04.
Habitat.—Fossil in Tertiary rocks of Sicily; Grotte (Stöhr).
Subgenus 3. Acanthocyrtis, Haeckel.
Definition.—Shell with numerous (twelve to twenty or more) terminal feet.
6. Cyrtophormis cylindrica, n. sp. (Pl. 77, fig. 17).
Shell rough, subcylindrical, with three annular septa. The fourth cylindrical joint is four times as long as the second and the third joints. These three joints are nearly equal in breadth. Pores small and numerous, almost square, in regular, transverse rows; two to three in the first joint, five to six in the second and in the third, fourteen to sixteen in the fourth joint. Cephalis flat, cap-shaped, with a short, pyramidal horn. Peristome half as broad as the shell, hyaline, with a coronal of numerous, very delicate, vertical feet.
