Arthropoda Nervous System
Ganglia, ventral nerve cords
Mulusca Nervous System
Brain, ganglia
Cnideria Nervous System
nerve net
Echinodermata Nervous System
nerve ring, radial nerves
Annelida Nervous System
Ganglia, ventral nerve cords
Nematoda Nervous System
Ganglia, dorsal and ventral nerve cords
Porifera Nervous System
none
Rotifera Nervous System
Ganglia or nerve ring
Platyhelminthes Nervous System
Ganglia, nerve cords
Chordata Nervous System
Brain, Dorsal nerve cord