NORTH EASTERN SPINY TAILED GECKO Diplodactylus williamsi Kluge, 1963
Attaining 9 cm the North Eastern Spiny Tailed Gecko is found throughout drier parts of eastern Australia. It is very similar in form and habit to the Eastern Spiny Tailed Gecko Diplodactylus intermedius from which it can be distinguished by having four instead of two rows of spines on the tail.
The spines exude a sticky fluid when this lizard is alarmed. A tree dweller, it is usually located resting under loose bark, in upright hollow logs or occasionally under rocks, during the day.

The above was from the book Australian Reptiles and Frogs by Raymond Hoser and now available on a fantastic CD-Rom along with a vast amount of other information, papers and the like on reptiles, frogs and other wildlife.