This copy is a hardback with a matt-finish. It is undated, however, it does have a ISBN number and is priced at 15p so probably published circa. early 1970s.
From the blurb;
"Every pond, big or small, natural or man-made, is a world of its own. Around, and beneath the surface is vigorous, active and unique life. There is a spider living inside a bubble-house ; a larva with its own snorkel tube ; a Boatman Beetle that rows itself about with its own hind legs ; another beetle, a Whirligig Beetle, that whirls round and round so fast the eye can scarcely follow it, and many, many more weird and wonderful animals.
A pond may look like just another patch of water, but beneath the green scum that often covers its surface, many amazing things are happening."
Excellent pages with some edge-wear. Does have a library stamp on the front flyleaf.