Electron microscopical studies reveal that the phasmids of Scutellonema brachyurum include socket and sheath cells which appear to be secretory. The phasmid includes an external cup-shaped ampulla filled with electron-dense material which may be lipopolysaccharide. The ampulla is continuous, with a receptor cavity surrounded by the socket and sheath cells. The dendrite receptor originates from a neuron and directs posteriorly through a receptor socket into the receptor cavity ending near the electron-dense plug. Serial sections through the dendrite receptor indicate that it does not conform to the typical 9+2 arrangement of microtubules characteristic of cilia in higher animals.