| I. Subfamily Coscinommida. (One single latticed shell.) | ||||||
| Spines all simple, not branched and not tubulous. | ||||||
| All spines of the same kind, | ||||||
| 88. Acanthosphæra. | ||||||
| Larger main spines and smaller by-spines, | ||||||
| 89. Heliosphæra. | ||||||
| Spines hollow conical tubes with porous walls, | ||||||
| 90. Conosphæra. | ||||||
| Between simple spines the pores prolonged in hollow tubes, | ||||||
| 91. Coscinomma. | ||||||
| Spines branched or forked. | ||||||
| Spines with lateral branches, | ||||||
| 92. Cladococcus. | ||||||
| Spines forked or dichotomous, | ||||||
| 93. Elaphococcus. | ||||||
| II. Subfamily Haliommida. (Two concentric latticed shells.) | ||||||
| A. Elatommida, one medullary and one cortical shell. | ||||||
| All spines equal, simple, | ||||||
| 94. Haliomma. | ||||||
| All spines simple, of two different kinds, | ||||||
| 95. Heliosoma. | ||||||
| Spines branched, | ||||||
| 96. Elatomma. | ||||||
| B. Diplosphærida, both shells cortical. | ||||||
| No by-spines, | ||||||
| 97. Leptosphæra. | ||||||
| Inner by-spines, | ||||||
| 98. Diplosphæra. | ||||||
| Outer by-spines, | ||||||
| 99. Drymosphæra. | ||||||
| Outer and inner by-spines, | ||||||
| 100. Astrosphæra. | ||||||
| III. Subfamily Actinommida. (Three concentric latticed shells.) | ||||||
| Radial spines not branched. | ||||||
| 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.) | ||||||
| Radial spines not branched. | ||||||
| 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.) | ||||||
| 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.) | ||||||
| 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. | ||||||
VI. Subfamily Spongiommida. (Spherical shell whole or partly spongy, with or without enclosed latticed medullary shells in the centre.) |  | I. Tribe Spongodrymida, without latticed medullary shell. |  | Spongy sphere solid. |  | Spines simple, | 111. Spongiomma. | ||
| Spines branched, | 112. Spongodrymus. | ||||||||
| Spongy sphere hollow. | | Spines simple, | 113. Spongechinus. | ||||||
| Spines branched, | 114. Spongothammus. | ||||||||
| II. Tribe Rhizoplegmida, with one single latticed medullary shell. |  | Medullary shell spherical. |  | Framework arising from the medullary shell, | 115. Spongopila. | ||||
| Framework separate from the medullary shell. | | No medullary by-spines, | 116. Rhizoplegma. | ||||||
| Medullary by-spines, | 117. Lychnosphæra. | ||||||||
| Medullary shell a simple cube. | | Framework arising immediately from the medullary shell, | 118. Centrocubus. | ||||||
| Framework separate from the medullary shell, | 119. Octodendron. | ||||||||
| III. Tribe Rhizosphærida, with two concentric latticed medullary shells. | | Framework arising from the medullary shell, | 120. Spongosphæra. | ||||||
| Framework separate from the medullary shell, | 121. Rhizosphæra. | ||||||||
| VI. Subfamily Spongiommida. (Spherical shell whole or partly spongy, with or without enclosed latticed medullary shells in the centre.) | ||||||||||
| I. Tribe Spongodrymida, without latticed medullary shell. | ||||||||||
| Spongy sphere solid. | ||||||||||
| Spines simple, | ||||||||||
| 111. Spongiomma. | ||||||||||
| Spines branched, | ||||||||||
| 112. Spongodrymus. | ||||||||||
| Spongy sphere hollow. | ||||||||||
| Spines simple, | ||||||||||
| 113. Spongechinus. | ||||||||||
| Spines branched, | ||||||||||
| 114. Spongothammus. | ||||||||||
| Medullary shell spherical. | ||||||||||
| Framework arising from the medullary shell, | ||||||||||
| 115. Spongopila. | ||||||||||
| II. Tribe Rhizoplegmida, with one single latticed medullary shell. | ||||||||||
| Framework separate from the medullary shell. | ||||||||||
| No medullary by-spines, | ||||||||||
| 116. Rhizoplegma. | ||||||||||
| Medullary by-spines, | ||||||||||
| 117. Lychnosphæra. | ||||||||||
| Medullary shell a simple cube. | ||||||||||
| Framework arising immediately from the medullary shell, | ||||||||||
| 118. Centrocubus. | ||||||||||
| Framework separate from the medullary shell, | ||||||||||
| 119. Octodendron. | ||||||||||
| III. Tribe Rhizosphærida, with two concentric latticed medullary shells. | ||||||||||
| Framework arising from the medullary shell, | ||||||||||
| 120. Spongosphæra. | ||||||||||
| Framework separate from the medullary shell, | ||||||||||
| 121. Rhizosphæra. | ||||||||||
Subfamily Coscinommida, Haeckel.
Heliosphærida, Haeckel, 1881, Prodromus, pp. 449, 450.
Definition.—Astrosphærida with one single spherical lattice-shell.
Genus 88. Acanthosphæra,[[122]] Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d.
Definition.—Astrosphærida with one simple lattice-sphere, covered with simple radial spines of the same kind.
The genus Acanthosphæra exhibits the most simple form of all Astrosphærida; a simple spherical lattice-shell, the surface of which is covered by radial spines of one and the same kind. The number of the latter is very variable, often twelve to twenty, regularly disposed; in other cases forty to sixty or more; and sometimes at each nodal-point of the network a spine is developed.