Family: CriconematidaeFemale: Body short, stout, 0.36-0.56 mm; annuli 70-80, strongly retrorse. Head offset, with one small, reduced, basal annulus, bearing a very large, rounded lip region. Lip region of six large lips, the two lateral lips with spacious cavities in their sclerotization and extending beyond it. Stylet 63-90 um. Body marked by 8-28 rows of scales, with a thick basal portion and thin elongated drawn-out posterior region to form a spine. A very light, delicate “fringe” of cuticle may be present. Tail conoid, with the scales more enlarged.
Male: Lateral lines three. Spicules 48 um. Caudal alae small or lacking. Tail conoid.
Juvenile: Known only for B. serratum. Head and tail resemble adult female. Cuticular ornamentation as ten rows of scales at midbody decreasing in number anteriorly and posteriorly. Each scale with flat pentagonal-shaped anterior base, rounded U-shaped posterior part with three to five fine serrations at tip.