The Protostomate Phyla

Annelida

Mollusca

Arthropoda

Phylum Annelida

• Segmented worms

• True body cavity

• Paired Protonephric excretory organs

• Paired ganglia with interconnecting nerves

• Complete digestive tract

Classes of Annelida

• Oligochaeta-few bristles– earthworms

• Polychaeta--many bristles, parapodia

• Hirudinea--leeches– Fusion of segments is called tagmatamization