The Porifera

collage - full view recommended 
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translations from hebrew - 
Upper text:
For centuries people thought that Sponges are plants
because they do not posses free-movement like most animals.
but the truth is that Sponges are sea-creatures, though their the most inferior amongst the multicellular creatures
and as such they make a special phylum in the animal-kingdom - The Porifera

Lower text:
The Sponges body is built as a skeleton between two layers of cells.
The skeleton is made of small spikes, some of them are made of calcium-spikes and some are made of formative spikes.
The spikes come in different shapes ans sizes. while some species have isolated spikes, in some species they touch each other and create a dense web.
[it's really inaccurate, but i took this text out of a really old textbook]

the short line on the right says: "fig.2 Visual Hallucinations"