Ischnothyreus

Ischnothyreus is a genus of oonopid spiders generally between 1.25 (smallest male) and 2.25 mm (largest female) long. They have six eyes; in at least the species I. peltifer and I. omus, the males have a curious knob or hook at the base of the fang. Ischnothyreus Simon, 1893