c8513c71_segmented_Worms__February_2007__Nematoda
[Phylum] Digestive System [Porifera] Intracellular [Cnidaria] Gastrovascular Cavity; intracellular [Platyhelminthes] Gastrovascular Cavity [Nematoda] 
Complete Gut
Unsegmented Worms: February 2007
Nematoda