Page:Scientific results HMS Challenger vol 18 part 2.djvu/578

Synopsis of the Genera of Phormocampida.

I. Subfamily Stichophormida. Mouth of the terminal joint open, simple.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Shell conical or pyramidal. Mouth wide open, not constricted.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Lateral ribs prolonged into the terminal feet,	636. Stichophormis.
				No lateral ribs. Feet free, terminal,	637. Phormocampe.
		Shell ovate or spindle-shaped. Mouth more or less constricted.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Lateral ribs prolonged into the terminal feet,	638. Artophormis.
				No lateral ribs. Feet free, terminal,	639. Cyrtophormis.
II. Subfamily Stichophænida. Mouth of the terminal joint closed by a lattice-plate.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	Six radial ribs or wings,			640. Artophæna.
		Nine radial ribs or wings,			641. Stichophæna.

Subfamily 1. Stichophormida, Haeckel, 1881, Prodromus, p. 439.

Definition.—Phormocampida with the terminal mouth of the shell open (vel Stichocyrtida multiradiata aperta).

Genus 636. Stichophormis,^[1] Haeckel, 1881, Prodromus, p. 439.

Definition.—Stichophormida (vel Stichocyrtida multiradiata aperta) with conical or pyramidal shell, bearing in its wall numerous lateral ribs, which are prolonged into terminal feet. Mouth not constricted.

The genus Stichophormis and the three following genera represent together the subfamily of Stichophormida, or of those multiradiate Stichocyrtida in which the mouth remains open; they may be derived therefore either from the Theophormida by increasing the number of the shell-joints, or from the Stichopilida by the interpolation of new radial ribs between the three primary ribs. Stichophormis may have been derived in the former way from Theophormis.

Subgenus 1. Stichophormium, Haeckel.

Definition.—Shell with six prominent longitudinal ribs, which are prolonged into six (sometimes five or seven) divergent free feet over the mouth.

1. Stichophormis pyramidalis, n. sp.

Shell slenderly pyramidal, with three annular septa, and six prominent radial ribs, which arise from the collar-septum, and are prolonged on the mouth into six free, divergent, pyramidal feet,

1. Stichophormis = Row-basket; στίχος, φορμίς.