Romer's tree frog
The adult frog is 15 to 25 mm long from nose to rear end.  It is the smallest frog in Hong Kong that was not brought by human beings from somewhere else.  Male frogs have white places on the first two toes of each front foot. The skin of the frog's back is brown in color.  There is a brown line between the eyes.  It has an X-shaped mark on its back.  There are dark marks on the back legs.  The skin of the frog's belly is cream-white in color. Some reports say there are dark spots on the belly and others say there are no spots.