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. |
Subfamily Coscinommida, Haeckel.
Heliosphærida, Haeckel, 1881, Prodromus, pp. 449, 450.
Definition.—Astrosphærida with one single spherical lattice-shell.
Genus 88. Acanthosphæra,[1] Ehrenberg, 1858, Monatsber. d. k. preuss. Akad. d.
Wiss. Berlin, p. 12.
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.
- ↑ Acanthosphæra = Spiny sphere; ἄκανθα, σφαῖρα.