Other
Algae
Algae
Algae 		Protists
Protista
Protista 		Bacteria
Bacteria
Bacteria 		Viruses
Viruses
Viruses 		Blue-green algae
Cyanobacteria
Cyanobacteria
Sponges
Porifera
Porifera 		Comb jellies & Sea walnuts
Ctenophora
Ctenophora 		Horseshoe crabs
Xiphosura
Xiphosura 		Sea spiders
Pycnogonida
Pycnogonida 		Echinoderms
Echinodermata
Echinodermata
Centipedes & Millipedes
Myriapoda
Myriapoda 		Worms
Annelida
Annelida 		Flatworms
Platyhelminthes
Platyhelminthes 		Roundworms
Nematoda
Nematoda 		Rotifers
Rotifera
Rotifera

Click above for photographs, maps, identification guides, and facts about each group.

Discover Life | All Living Things | Identification guides

Updated: 16 July, 2006