Looking up he observed that the small boy was gone.

With a bound he stood erect, one foot on the gunwale and hands clasped ready to dive, when a glance revealed the fact that Kathy was smiling broadly! "Don't jump!" she said.

"He is only after a fish." Even while she spoke Nigel saw the brown little fellow shooting about like a galvanised tadpole, with a small harpoon in his hand! Next moment he appeared on the surface shouting and spluttering, with a splendid fish on the end of his harpoon! Both were hauled into the boat, and very soon after they drew near to land.
In the shallow water Nigel observed some remarkable creatures which resembled hedgehogs, having jaws armed with formidable teeth to enable them to feed, Kathy said, on coral insects.

File-fishes also drew his attention particularly.

These were magnificently striped and coloured, and apparently very fearless.
"What convenient tails they have to lay hold of," remarked our hero, as they slowly glided past one; "I believe I could catch it with my hand!" Stooping swiftly as he spoke, he dipped his arm into the water, and actually did grasp the fish by its tail, but dropped it again instantly--to the shrieking delight of the urchin and Kathy,--for the tail was armed with a series of sharp spines which ran into his hand like lancets.
This was an appropriate conclusion to a day that would have been otherwise too enjoyable.