Australian snakes fall into five families:
Australia is home to a large number of different species of snakes. Many different species are similar in appearance and are extremely difficult to differentiate from one another while some snakes display high variations in appearance within a particular species. For these reasons experts rely on scale patterns to make a positive identification. Australia is the only continent where venomous snakes outnumber non venomous snakes.
Reference: A Complete Guide to Reptiles of Australia