Subgenus 3. Tuscarilla, Haeckel.
Definition.—Shell with three perradial equidistant feet, and with four crossed equidistant teeth around the mouth.
7. Tuscarora belknapii, John Murray.
Tuscarora belknapii, John Murray, 1879, in litteris, Narr. Chall. Exp., vol. i. p. 226, pl. A, figs. 15, 15a-15d.
Shell pear-shaped, with three lateral perradial feet in the upper third, and four crossed teeth around the mouth. The three arcuate feet are thin, cylindrical, covered with small curved thorns, and arise at the base of the peristome, between the upper and middle third of the shell; they ascend diverging to the height of the mouth, and are then curved downwards in a large arc, twice to three times as long as the shell. The base of each foot is dilated and pierced by three pedal pores. The four thin and long teeth of the peristome are similar to the feet, ascend in a slightly diverging manner, and are so placed that two opposite lie in the sagittal plane (or in the radius of the dorsal odd foot), whilst the two others are opposite in the frontal plane (perpendicular to the former). The base of each tooth exhibits two large ovate dental pores.
Dimensions.—Length of the shell 2.5, breadth 1.5.
Habitat.—South Pacific, Station 293, depth 2025 fathoms.
Genus 718. Tuscarusa,[[334]] n. gen.
Definition.—Tuscarorida with four radial aboral feet and a variable number of circoral teeth.
The genus Tuscarusa differs from the preceding closely allied Tuscarora in the possession of four radial feet instead of three. The mouth of the single observed species is a narrow sagittal fissure, and armed with two opposite teeth (a dorsal and a ventral, as in the subgenus Tuscaretta). The four lateral feet form a cross, and lie opposite in pairs, in two diagonals of the square, which is bisected by the sagittal mouth.