Head capsule with a pair of folding, cephalic fans (cf);
Abdominal segments 5-8 swollen (ab), end abdominal
segment with numerous radiating rows of
minute hooks (rh)

Head capsule without cephalic fans; End abdominal
segments (ab) not swollen or with radiating rows of
hooks; Anal proleg(s) (pl) bearing crotchets (ct)
sometimes present.