| Green Tree Snake, Dendralaphis punctulata - Scales smooth in 13 (rarely 11 or 15 )rows with vertebral series enlarged. Anal & subcaudal scales divided. Loreal scales present.
Brown Tree Snake, Boiga irregularis - Scales smooth & weakly glossed, in 19-23 midbody rows; vertebral row enlarged & hexagon shaped. Anal scale single & subcaudals divided. Loreal scales present.
Rough Scaled Snake, Tropidechis carinatus - 23 midbody rows, Anal & subcaudal scales single.
Keelback,Tropidonophis mairii - Scales strongly keeled in 15 midbody rows. Anal & subcaudal scales divided. Loreal scale present.
All this is taken from A complete guide to Reptiles of Australia, Steve Wilson, Gerry Swan | 
