Measurements (from Hooper, 1958)
Body cylindrical, tapering at both ends. Cuticle finely annulated, the annules 0.8-1.0 u wide in mid body region. Lateral fields prominent, marked by three incisures, occupying between a quarter and a fifth of the total body-width. Lateral fields begin about half-way between head and oesophageal bulb and end midway between anus and tail terminus. Head slightly offset, without annulations. An end-on view shows six lips but no papillae or amphidial openings are visible. Stylet 10 u long made up of the usual two parts with distinct basal thickenings. Stylet tip surrounded by guide ring which appears star-shaped when seen from the front and as two short rods in lateral view. First region of oesophagus narrow with well marked lumen followed by prominent, muscular, median bulb in the centre of which is a conspicuous valve with crescentic thickenings. Elongated oesophageal glands lying dorsally along intestine and about three body-widths long: dorsal gland duct opening into lumen of oesophagus just in front of valve. Intestine begins as tube immediately behind median bulb, widens gradually and runs straight to narrow rectum which is twice as long as the anal body-width. Anus distinct; behind it the tail narrows suddenly and then gradually tapers to the tip; tail over four times as long as the anal body-width. Tail terminus convex-conoid with sharply pointed, ventrally placed, mucro. Tail curves ventrally when relaxed by gentle heat and has a finger like appearance; hence the specific epithet of dactylocercus. Nerve ring situated just behind median oesophageal bulb. Excretory pore on ventral surface usually just in front of nerve ring but may be as far forward as centre of median bulb. Ovary outstretched, consisting of a single row of about twelve oocytes. Oviduct short, only one egg seen at a time in the uterus. Eggs just over two and a half times as long as broad. Post vulval sac short, usually less than one body-width long. Vagina directed obliquely backwards. Vulva transverse slit about one third of a body-width long.
No males have been found.
Type habitat: Pot of soil growing young Sitka spruce trees, Picca sitchensis (Borg.) Carr. -- Nematology Department, Rothamsted.