MacGillivray, 1921
Appearance in life
Scale cover of adult female circular or broadly oval, highly convex, thick, with central or submarginal exuviae and a thick ventral scale. Scale cover of immature male similar to female but elongate, with apical exuviae.
Morphology
Adult female not pupillarial; body subcircular to broadly pyriform, usually membranous except for thickened cuticle in parts of pygidium. Pygidium with a pattern of dorsal sclerotization; with only median lobes fully developed; second, third and possibly fourth lobes suggested by slightly enlarged and sclerotized prominences amongst the irregularities along the margin, these lobes not sufficiently defined to decide whether they are unilobulate or bilobed. Median lobes parallel to longitudinal axis of body, heavily sclerotized, longer than wide, very close together, with outer margin sometimes notched; each lobe with a large basal sclerosis projecting arising from its base. Paraphyses absent. Dorsal marginal setae at outer basal corner of each pygidial segment flagellate, not longer than median lobe. Plates very small, slightly fimbriate, present between median lobe and position of second lobe only, or absent. Anus oval to rounded triangular, usually smaller than median lobe, situated between anterior and posterior one-third length of pygidium; vulva situated between centre and anterior third of pygidium. Short, slender, obscurely 2-barred ducts present in a marginal zone on both surfaces of pygidium and preygidium; marginal ducts may be present between median lobes, always present along pygidial margin; submarginal ducts numerous, sometimes arranged in intersegmental rows or series between segments VIII and VII, VII and VI and VI and V on each side, otherwise irregularly arranged. Preygidium with submarginal ducts present, the marginal cuticle of the more posterior segments more or less thickened, sometimes slightly crenulate; without plates or duct tubercles. Perivulvar pores absent or present in 4 small groups. Stigmatic disc pores absent; antennae widely spaced, each bearing one seta and sometimes with a sclerotized spur.