DESCRIPTION Male: Posterior part of body curves ventrally when killed by heat. Onchiostyle characteristic; tip lying free in the pharyngeal lumen just behind the stoma wall. About 18 u behind the oral aperture the lining of the pharyngeal lumen is attached dorsally and laterally to the onchiostyle, where it forms the so-called "guide ring". Excretory pore about one body-width behind the nerve ring. Three ventro-median cervical papillae located anterior to