“Where—where? Ah, I see; those two knobs close together?”

“Yes; the brute must have taken alarm, and glided back into the river. It is evidently watching us.”

“Beg your pardon, Master Carey. I thought it was games. Well, sir, it’s a good job you see that chap. We know he harnts the place. Who knows but what you might ha’ took a fancy to bathe there some day?”

“I was thinking what a beautiful place it would be, because there’d be no fear of sharks in such a shallow place.”

“No sharks perhaps, sir, but they’re innocent babies to a thing like that. Why, he might have swept you in with his tail before you’d undressed yourself. You and clothes and all.”

“What are you going to do?” said the doctor, as the old sailor handed Carey the gun and stooped to pick up a piece of coral as big as a child’s head.

“On’y going to show him, cunning as he is, thinking that he’s snugly hid under water, that we can see him, and that we know what’s the meaning of two knobs on the water.”

The doctor nodded and looked on, Carey feeling an intense longing to follow the old sailor’s example, but feeling that it would be some time before he could throw a heavy stone.

Meanwhile Bostock walked slowly to the edge of the water, and then along towards the sea, reducing the distance till he was not above five-and-twenty yards from the floating reptile, when he stopped short and pitched the lump of coral with pretty good aim; but as it described an arc and was still in the air, there was a tremendous wallow, a wave rose on the surface, and they could trace the course taken by the monster, which, with one tremendous stroke of its powerful tail, glided right away towards the sea.

“Wish it had made a dint in his skull,” said Bostock. “Beasts! how I do hate ’em! Dessay there’s lots more, so we shall have to take care.”