Diagnosis: This very common species can be diagnosed by body length 0.5-0.8 mm; head 5-7um wide at base, about half as high, not offset; sylet delicate with tiny knobs, 9-12 um long; oesophagus 89-124 um long with an oval median bulb, slight central thickenings at 40-48%; posterior glandular region pear-shaped, bulb-like; vulva wide, simple slit, vagina straight with thin walls; postuterine sac well-developed but usually not exceeding one vulval body diameter; spermatheca offset, oval to elongated; tail elongated; usually straight with very fine but usually not filiform tail end; tail in most specimens 1-1.5 times vulva-anus distance.  Annuli usually 1-1.5 um wide, mostly faint; lateral field four lines, two inner lines sometimes difficult to observe. F. conicephalus is synonymized, although the description gives a stylet length of 12-17 um, the drawings suggest this is an error.

-Raski and Geraert, 1986