Dimensions.—Shell 0.06 long, 0.09 broad; lateral feet 0.1, sagittal feet 0.05 long.
Habitat.—Tropical Atlantic, Station 347, depth 2250 fathoms.
3. Tessarospyris seminulum, Haeckel.
Petalospyris seminulum, Stöhr, 1880, Palæontogr., vol. xxvi. pl. iii. fig. 12.
Shell subspherical, smooth, with slight sagittal stricture and small circular pores; some larger pores on both sides of the ring. Basal plate with two large (lateral) pores only. Four feet nearly equal, short, conical, divergent, scarcely one-fourth as long as the shell.
Dimensions.—Shell 0.06 long, 0.08 broad; feet 0.016 long.
Habitat.—Fossil in Tertiary rocks of Sicily (Grotte), Stöhr.
Subfamily 4. Hexaspyrida, Haeckel.
Definition.—Zygospyrida hexapoda, with six descending basal feet; three of these are primary (one odd caudal and two paired pectoral feet), the other three are secondary, opposed diametrically to the former and alternating with them (one odd sternal and two paired tergal feet).