“The second was chocolate mints.”

“Oh, my, weren’t they good?” Crullers added.

“Third, a full and complete Manual on Conchology and Sea-life, suitable for young persons marooned on an isle,” concluded Polly, returning with a pair of scissors to cut the twine. “I wonder what this is?”

It was addressed, as the other parcels had been, simply to “The Yacht Club, Lost Island, Eagle Bay, Maine.” Polly opened it while the rest stood around. One wrapping after another was removed, and finally a box appeared. When this was opened, there lay a microscope, a fine one, with several different removable lenses for observing specimens.

“Well, what a darling, tasty old pirate he is,” exclaimed Polly, joyously. “He seems to know all our needs. We’ll have to send something to him in return, girls.”

“I’ll make him a shell portìere to hang in front of his cave,” said Kate, soberly. Scarcely had she spoken when a strange and unusual sound broke the stillness of the bay.

“That sounds like a motor boat,” Polly said, instantly. “Maybe it’s the one from the Hippocampus.”

It was surely a motor boat, but not the bright-railed, mahogany-trimmed one from the Hippocampus. This was white, with a high, pointed prow, a cabin, and a cockpit similar to Nancy’s knockabout. But there the resemblance ended. The mast had been removed, and a small gasoline engine provided the power.

“I can see the name on the prow,” called Ted presently. “It’s the Natica.”

“Natica means a sea snail,” Ruth explained, with absent-minded reversion to lessons, but Polly dropped her shells helter-skelter into the hammock, and rose.