Platybursa compressa, Haeckel, 1881, Prodromus, p. 429; Atlas, pl. 53, fig. 7.
Shell smooth, nearly discoidal circular, markedly compressed in the sagittal direction, with slight basal stricture. Pores very numerous, irregular polygonal, with thin bars. Basal plate with four very large pores. Six feet short, conical, nearly horizontally expanded. Two sagittal feet (caudal and sternal) larger, about half as long as the shell (shortened in the figure). The two sternal feet larger than the two small or rudimentary tergal feet.
Dimensions.—Shell 0.15 long, 0.13 broad; feet 0.02 to 0.06 long.
Habitat.—Central Pacific, Station 271, depth 2425 fathoms.
Subfamily 5. Pentaspyrida, Haeckel, 1881, Prodromus, p. 442.
Definition.—Zygospyrida pentapoda, with five descending basal feet, one odd caudal foot, and two pairs of lateral feet (two anterior or pectoral, and two posterior or tergal feet).
Genus 456. Clathrospyris,[[74]] Haeckel, 1881, Prodromus, p. 442.
Definition.—Zygospyrida with five basal feet and one apical horn.
The genus Clathrospyris and the two following closely allied genera represent together the small subfamily of Pentaspyrida, differing from the other Zygospyrida in the possession of five descending feet on the basal face. Three of these are the primary cortinar feet (of Cortiniscus, Plagoniscus, Tripospyris, &c.), whilst the two others are secondary tergal feet. The Pentaspyrida may therefore be probably derived from the Hexaspyrida by loss of the odd anterior or sternal foot.
1. Clathrospyris camelopardalis, n. sp.