Arbanitis melancholicus (An armoured trapdoor spider)

Idiopidae family

A large dark brown trapdoor spider endemic to NSW. The venter (ventral side of abdomen) has a variable pattern of dark scattered spots. Most of the diagnostic features for the species are only evident in the male under microscopic examination of the pedipalps. These include a tiny bump (apophysis) midway along the embolus (the pointed tip of the bulb of the pedipalp) and the presence of many short, thick spines on the dorsal side of the cymbium (the segment of the pedipalps just before the bulb). The dorsal side of the metatarsus of the last pair of legs lacks spines.