Family: Mimetidae (Pirate Spiders)
Size: 4-8 mm body length
References: Whyte and Anderson
About the Pirate Spider
These are known as Pirate Spiders because they shake other spiders webs to imitate struggling prey, and then attack the spider when it comes to investigate.
Note that dead spiders usually fade in colour, so nearly all the spiders will look blacker or darker in colour in real life than they do in the photos of dead spiders from the museum.
Photo taken at Australian Museum, Sydney. High Resolution 3652 x 2564.