Page:Scientific results HMS Challenger vol 18 part 2.djvu/148

Synopsis of the Genera of Zygospyrida.

I. Subfamily Tripospyrida. Three basal feet. (One odd caudal and two paired pectoral.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Apex of the shell with one horn,					441. Tripospyris.
		Apex of the shell with three horns,					442. Triceraspyris.
		Apex of the shell without horns,					443. Tristylospyris.
		Apex with two large coryphal holes, right and left,					444. Cephalospyris.
II. Subfamily Dipospyrida. Two basal lateral feet. (Originally the two pectoral feet.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Two feet free, not grown together.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Feet simple, not branched, without lateral spines.	$\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}$	One horn,	445. Dipospyris.
						No horn,	446. Brachiospyris.
				Feet branched like a tree.	$\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}$	One horn,	447. Dendrospyris.
				Feet with a series of lateral spines.	$\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}$	One horn,	448. Dorcadospyris.
		Two feet grown together and uniting to form a ring. Apex with a horn.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Feet simple,			449. Gamospyris.
				Feet with a series of lateral spines,			450. Stephanospyris.
III. Subfamily Tetraspyrida. Two sagittal and two lateral feet.	$\scriptstyle {\left.{\begin{matrix}\ \\\ \end{matrix}}\right\}\,}$	Feet simple, not branched.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Apex with one horn,			451. Tetraspyris.
				Apex without a horn,			452. Tessarospyris.
IV. Subfamily Hexaspyrida. Six basal feet.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	Two sagittal, two pectoral, and two tergal feet.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Apex with one horn,			453. Hexaspyris.
				Apex with three horns,			454. Liriospyris.
				Apex without a horn,			455. Cantharospyris.
V. Subfamily Pentaspyrida. Five basal feet.	$\scriptstyle {\left.{\begin{matrix}\ \\\\\ \ \end{matrix}}\right\}\,}$	One caudal, two pectoral, and two tergal feet.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \ \end{matrix}}\right.}$	Apex with one horn,			456. Clathrospyris.
				Apex with three horns,			457. Ægospyris.
				Apex without a horn,			458. Pentaspyris.
VI. Subfamily Therospyrida. Four paired lateral feet. (Two pectoral and two tergal.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Apex with one horn,					459. Zygospyris.
		Apex with three horns (one apical and two frontal),					460. Elaphospyris.
		Apex with two lateral or frontal horns,					461. Taurospyris.
		Apex without a horn,					462. Therospyris.
VII. Subfamily Polyspyrida. Numerous (seven to twelve or more) basal feet.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Apex with one horn,					463. Petalospyris.
		Apex with three horns (one apical and two frontal),					464. Anthospyris.
		Apex with numerous horns,					465. Ceratospyris.
		Apex without a horn,					466. Gorgospyris.
VIII. Subfamily Circospyrida. No basal feet.	$\scriptstyle {\left\{{\begin{matrix}\ \\\ \end{matrix}}\right.}$	Apex with one horn,					467. Circospyris.
		Apex without a horn,					468. Dictyospyris.