Key to Classes of NEMATODA

1 Phasmids absent; amphids pocket-like; caudal papillae absent or few in number; oesophagus cylindrical or with oesophageal glands free in the pseudocoelom forming a stichosome; excretory system without lateral canals, terminal duct not lined with cuticle........................................................................................ Enoplea

- Phasmids present; amphids pore-like; caudal papillae usually numerous (basic number 21); oesophagus never in the form of a stichosome; excretory system with lateral canals, terminal duct lined with cuticle......................... Chromadorea