|Kauaʻi cave wolf spider|
Gertsch, 1973 
The Kauaʻi cave wolf spider (Adelocosa anops, the only species in the genus Adelocosa), also known to local residents as the "blind spider", is only known to occur in a few caves in a lava flow with an area of 10.5 km2 (4.1 sq mi) in the Kōloa–Poʻipū region of Kauaʻi, Hawaiian Islands, and only six populations are known to exist. While their nearest surface-dwelling relatives have large eyes, this species has completely lost its eyes. They reach a body length around 20 mm (0.8 in), and are reddish brown and completely harmless to people. Unlike most wolf spiders, it produces only 15 to 30 eggs per clutch. The female carries the egg sac in her mouthparts until the spiderlings hatch.
One of its primary prey species is the Kauaʻi cave amphipod, Spelaeorchestia koloana, which is only known from nine populations and reaches about 10 mm (0.4 in) in length. These feed on decomposing plant matter. The Kauaʻi cave wolf spider was discovered in 1973. Counts have never documented more than 30 spiders or 80 amphipods.