Cockerell, 1897
Appearance in life
Scale cover of adult female very hard, circular, moderately to highly convex, black or dark brown, with central exuviae; ventral scale dark, thick and hard around margins, thinner and white in centre. Scale cover of immature male similar to female but smaller, oval with exuviae towards one end.
Morphology
Adult female not pupillarial; body appearing approximately circular in a slide preparation; prosoma more or less membranous except for expanded cephalic margin, which forms a median lobe that becomes heavily sclerotized in mature females. Marginal tubercle or spur normally present, probably formed by modification of the eye. Pygidium short and wide, projecting little, apical angle obtuse, with a definite pattern of sclerotization: with a median flask-shaped area arising from between the third lobes and extending anteriorly; a pair of small, elongate areas, each arising from base of third lobe; and a third pair of elongate and laterally ill-defined sclerotized areas, each arising from just lateral to third lobe and extending forward to meet the lateral dorsal scar. Pygidium with 4 pairs of unilobulate lobes; lobes often notched, especially on outer margins, each of which may have several notches especially on outer lobes; margin anterior to fourth lobes crenulate or somewhat toothed, more or less sclerotized. Lobes parallel to longitudinal axis; not clearly graduated in size; median lobes not obviously elongate, well sclerotized; second lobe often smaller than median or third lobes, well sclerotized. Conspicuous paraphyses or scleroses arising from bases of lobes, interlobular spaces and from a short section of margin anterior to fourth lobe, at least some paraphyses as far laterally as third lobes much longer than a median lobe. Plates quite slender, slightly shorter than or slightly longer than lobes, those between the lobes often fringed; 0 or 2 present between median lobes, 1 or 2 between median and second lobes, 2 or 3 between second and third lobes; a few small, fleshy projections sometimes present anterior to fourth lobe. Anus oval, usually shorter than median lobe, situated at centre or about the posterior third of length of pygidium from its apex; vulva situated approximately at centre of pygidium. Dorsal macroducts usually very long and slender, usually moderate in number; 0 or 1 marginal duct between median lobes, 1 between median and second lobes, 2 or 3 between second and third lobes and 2-4 between third and fourth lobes on either side; a series of marginal ducts present along pygidial margin anterior to fourth lobe, sometimes on the ventral margin as well. Submarginal ducts usually arranged in 3 poriferous furrows or intersegmental series between segments VIII and VII, VII and VI and VI and V on each side. Ventral prepygidial marginal ducts often present. Perivulvar pores absent or present in 4-5 groups. Stigmatic disc pores absent; antennae situated fairly near mid-line, each bearing one seta and a small, sclerotized spur.