Genus Hexatylus
Goodey, 1926
Anguillulina (Hexatylus Goodey, 1926) (Schneider 1939)
Neotylenchus Steiner, 1931
Anguillulina (Neotylenchus Steiner, 1931) (Schneider 1939)
Scytaleum Andrássy, 1961

    Neotylenchinae.  Entomoparasitic generation: Adult female in insect haemocoel, elongate-obese.  Males and preadult infective female resembling those of most Sphaerularioidea, female with much larger stylet bearing basal knobs and having enlarged oesophageal glands, extremely elongate uterus filled with minute sperm and immature ovary.  Preadult female penetrates an insect host and matures in its haemocoel.  Free-living, mycetophagous generation:  Female: Body veriform, straight or slightly arcuate ventrally upon relaxation, about 1 mm long (0.76 - 0.9 mm long, maximum width 45 - 57 um in type species).  Cuticle finely striated.  Lateral fields each with six incisures, not areolated.  Cephalic region very low, continuous or slightly offset, smooth;  labial disc absent; oral opening circular, six inner labial and four cephalic papillae present; amphid apertures small, labial but slightly posterior to level of cephalic papillae; framework six-sectored at base, 12-sectored anteriorly. Stylet slender, about 8 -12 um long; conus shorter than shaft; basal knobs in type species duplex or bifid so that they appear as six swelllings; two to three guidings rings present around shaft.  Some stylet protractors pass through framework to attach to cuticle on top of head.  Oesophagus cylindroid or fusiform.  Nerve ring circum-intestinal.  Excretory pore behind nerve ring.  Oesophageal glands overlapping intestine, dorsal gland larger that subventrals. Vulva a long transverse slit, usually at less than two body-widths from anus.  Vagina directed anteriorly.  No postvulval uterine sac.  Prodelphic.  Uterus with a prominent crustaformeria.  Eggs elongate-oval; one or two eggs in uterus at any one time.  Oviparous.  Oviduct with two consecutive rings of four cells each or two rows of seven to nine cells (Geraert, 1976).  Ovary outstretched, tip may be reflexed.  Female tail elongate-conoid, pointed, may be filiform.  Rectum and anus distinct; rectum acts as a feeding pump.  Male: Stylet present.  Testis producing minute rounded sperm.  Spicules anteriorly expanded, arcuate, cephalated.  Gubernaculum simple, fixed.  Bursa distinct, terminal or subterminal.  Juveniles essentially similar to female.

(Description- Siddiqi, 2000)

Type species
    Hexatylus viviparus Goodey, 1926
    syn.:  Anguillulina (Hexatylus) vivipara (Goodey) W.Schneider, 1939
           Iotonchium vivaparum (Goodey) Filipjev & Schuurmans Stekhoven, 1941
           Neotylenchus abulbosus Steiner, 1931
           Anguillulina abulbosus (Steiner) Schneider, 1939
           Hexatylus abulbosus (Steiner) Goodey, 1933
           Iotonchium vivaparum (Steiner) Filipjev & Schuurmans Stekhoven, 1941

Other Species
           Hexatylus acutus (Thorne, 1941) Siddiqi, 1986
                syn.: Neotylenchus acutus Thorne, 1941 (N. apiculatus in Thorne, 1941 = lapsus calami)
           H. coprophagus Goodey, 1938
                syn.: Iotonchium coprophagum (Goodey) Filipjev & Schuurmans Stekhoven, 1941
                       Neotylenchus coprophagus (Goodey) Thorne, 1941
           H. kirjanovae (Izatullaeva, 1969) Siddiqi, 1986
                syn.: Neotylenchus kirjanovae Izatullaeva, 1969
           H. mucronatus (Izatullaeva, 1969) Siddiqi, 1986
                syn.: Neotylenchus mucronatus Izatullaeva, 1969
           H. mulveyi Das, 1964
           H. nudus (Thorne & Malek, 1968) Siddiqi, 1986
                syn.: Neotylenchus nudus Thorne & Malek, 1968
           H. vigissi Skarbilovich, 1952
                syn.: Neotylenchus vigissi (Skarbilovich) Goodey, 1963
                       Scytaleum vigissi (Skarbilovich) Andrássy, 1961

DNA Sequences Obtained
Specimen: Collected:
Westplace Unknown