Page:Scientific results HMS Challenger vol 18 part 2.djvu/291

Rh 1. Haliphormis lagena, n. sp. (Pl. 97, fig. 5)

Shell bottle-shaped, twice as long as broad, tapering towards both ends, with nine longitudinal curved ribs. These are connected by irregular transverse beams, and the quadrangular meshes, so produced, are filled up by irregular, delicate, arachnoidal framework. The constricted mouth is half as broad as the middle part of the shell and surrounded by nine slender convergent feet, the free distal ends of the ribs. The apex bears a small knob with an oblique horn, perhaps the rudimentary cephalis of Sethamphora or Sethopyramis (?).

Dimensions.—Shell 0.6 to 0.7 long, 0.3 to 0.4 broad.

Habitat.—South Atlantic, Station 332, depth 2200 fathoms.

2. Haliphormis costata, n. sp.

Shell campanulate, somewhat longer than broad, with twelve prominent longitudinal ribs, alternating with twelve rows of regular circular pores. Mouth constricted half as broad as the shell, with twelve long triangular feet, formed by the free distal ends of the ribs. Apical horn short and stout, triangular pyramidal.

Dimensions.—Shell 0.12 long, 0.1 broad; mouth 0.07 long.

Habitat.—Central Pacific, Station 271, depth 2425 fathoms.

Definition.— (vel Monocyrtida multiradiata aperta) with numerous radial ribs in the wall of the campanulate or urceolate shell, prolonged into free terminal feet. Apex without horn.

The genus Archiphormis differs from the preceding Haliphormis, its probable ancestral form, in the absence of the apical horn. The number of the longitudinal ribs, which are prolonged into terminal feet, is from six to nine or twelve or even more.

1. Archiphormis cancellata, Haeckel.

(?) Halicalyptra cancellata, Ehrenberg, 1854, Monatsber. d. k. preuss. Akad. d. Wiss. Berlin, p. 243.

Shell cup-shaped or campanulate, with six prominent ribs, prolonged into six terminal triangular feet, one-third as long as the shell. Ribs connected by five or six transverse horizontal rings; meshes between them rounded squarish. (As Ehrenberg has given no figure of this species, its identity with the Challenger specimen is doubtful.)

Dimensions.—Shell 0.08 long, 0.06 broad; mouth 0.04 broad.

Habitat.—North Atlantic, Station 353, depth 2965 fathoms.