Page:Scientific results HMS Challenger vol 18 part 1.djvu/416

Synopsis of the Genera of Astrosphærida.

I. Subfamily Coscinommida. (One single latticed shell.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Spines all simple, not branched and not tubulous.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	All spines of the same kind,	088. Acanthosphæra.
				Larger main spines and smaller by-spines,	089. Heliosphæra.
		Spines hollow conical tubes with porous walls,			090. Conosphæra.
		Between simple spines the pores prolonged in hollow tubes,			091. Coscinomma.
		Spines branched or forked.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	Spines with lateral branches,	092. Cladococcus.
				Spines forked or dichotomous,	093. Elaphococcus.
II. Subfamily Haliommida. (Two concentric latticed shells.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	A. Elatommida, one medullary and one cortical shell.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	All spines equal, simple,	094. Haliomma.
				All spines simple, of two different kinds,	095. Heliosoma.
				Spines branched,	096. Elatomma.
		B. Diplosphærida, both shells cortical.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	No by-spines,	097. Leptosphæra.
				Inner by-spines,	098. Diplosphæra.
				Outer by-spines,	099. Drymosphæra.
				Outer and inner by-spines,	100. Astrosphæra.
III. Subfamily Actinommida. (Three concentric latticed shells.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Radial spines not branched.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	All spines equal,	101. Actinomma.
				Larger main spines and smaller by-spines,	102. Echinomma.
		Radial spines branched or forked,			103. Pityomma.
IV. Subfamily Cromyommida. (Three concentric latticed shells.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right.}$	Radial spines not branched.	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \ \end{matrix}}\right.}$	All spines equal,	104. Cromyomma.
				Larger main spines and smaller by-spines,	105. Cromyechinus.
		Radial spines branched or forked,			106. Cromyodrymus.
V. Subfamily Caryommida. (Numerous, five to ten or more, concentric latticed shells.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Two medullary shells and three or more cortical shells (lattice work ordinary),			107. Caryomma.
		No medullary shells (lattice work arachnoidal); three-sided prismatic spines, with verticils of three forked branches. (Arachnosphærida.)	$\scriptstyle {\left\{{\begin{matrix}\ \\\\\ \\\ \\\ \\\ \\\ \\\ \ \end{matrix}}\right.}$	Triangular meshes, simple bars, without diagonal bars,	108. Arachnopila.
				Triangular meshes, simple bars; diagonal bars between the shells,	109. Arachnopegma.
				Polygonal meshes, bars branched,	110. Arachnosphæra.