Genus 452. Tessarospyris,[[70]] Haeckel, 1881, Prodromus, p. 442.
Definition.—Zygospyrida with four basal feet crossed in pairs (two sagittal and two lateral). Apex without horn.
The genus Tessarospyris differs from the preceding Tetraspyris, its ancestral genus, in the absence of the apical horn, and therefore bears to it the same relation that Tristylospyris does to Tripospyris.
1. Tessarospyris clathrobursa, n. sp. (Pl. [53], fig. 8).
Clathrobursa dictyopus, Haeckel, 1881, Prodromus, p. 439, and Atlas, pl. liii. fig. 8.
Shell nearly ovate, strongly compressed, smooth, one and a half times as long as broad, with deep sagittal stricture in the basal half. Pores very small and numerous, irregularly roundish. Basal plate with four very large triangular holes, two larger (posterior) cardinal, and two smaller (anterior) jugular pores; above the latter (on the frontal face) two large mental pores. Two pectoral feet large, half as long as the shell, at the base fenestrated, vertical, and parallel. Two sagittal feet much smaller, nearly horizontal, pyramidal (the caudal larger than the sternal foot). Two longitudinal pectoral ribs arise on the frontal face.
Dimensions.—Shell 0.21 long, 0.14 broad; lateral feet 0.1, sagittal feet 0.02.
Habitat.—South Atlantic, Station 332, depth 2200 fathoms.
2. Tessarospyris nuciformis, n. sp.
Shell nut-shaped, papillate, with deep sagittal stricture. Pores irregular roundish, on both sides of the ring three to six times as large as on the lateral sides. Basal plate with four large pores. Two pectoral feet cylindrical curved, twice as long as the shell and as the two sagittal feet; the caudal is much stronger than the sternal foot.