Scorpion Tailed Spider
Arachnura higginsi
Family: Araneidae ID: Koch

Habitat and Biology 
  The tailed spider builds a permanent but incomplete orb 
  web near the ground close to foliage. The web is suspended on an angle and has 
  a V-shaped section missing from the top of the web. In late summer and autumn, 
  the female produces a series of woolly yellowish egg sacs which she strings 
  up in a line from the centre of the web to fill the missing section. The egg 
  sacs are often camouflaged with debris and the spider sits at the bottom of 
  the string in the centre of the web. The female spider can curl her tail up 
  over her back like a scorpion if she is disturbed. The tip of the tail often 
  has a number of black lobes which are soft and unable to sting or inflict any 
  sort of wound. These spiders are widespread throughout Australia and are often 
  found in large numbers near water. 
Colour
  Male: Similar to female but more reddish.
  Female: Body various shades of brown but most commonly 
  fawn, with a black tip on the end of the abdomen. Legs and cephalothorax may 
  be darker brown. Juveniles may be yellow through to pink.
Form
  Small cephalothorax, body broad with a two horn like projections 
  protruding over the cephalothorax then tapering into a tail with a black tip. 
  When disturbed the spider curls its tail up over the body similar to a scorpion. 
  It is unable to sting and is quite harmless. Male much smaller than female with 
  no tail.
Body Length
  Male: 2mm
  Female: 15mm
Web type
  Builds an inclined, incomplete orb web missing a V-shaped 
  section at the top.
Bite
  Bites by this spider are rare. Symptoms are minor and may include 
  local pain and swelling.