, too!" said Chet, thoughtfully. "Tony said they were
quarreling over money."

"There is something that needs looking into about Tony Allegretto,"
declared Mother Wit, seriously. "Don't you think so, Chet?"

"It might be well to find out what the money was, and where they got it
to quarrel over," agreed Chet, slowly.

"Pirate gold, of course!" laughed Bobby Hargrew, from another boat.
"Don't spoil all the romance of this treasure hunt by suggesting that
the buried loot is merely the proceeds of the sale of a banana stand
that the two Italians owned in partnership."

CHAPTER XXIII

BILLY'S GREAT DIVE

But both Chet and Laura Belding were thoughtful for the rest of the way
to the island. The others seemed to see nothing significant in what
Billy had said about the two Italians, or the suggestion the twins had
made that the quarreling men were identical with Tony Allegretto, the
trained monkey's master, and his fellow countryman, whom the police had
driven away from Cavern Island.

"We ought to find some clue to the buried treasure, something like Poe's
'Gold Bug,'" suggested Nellie Agnew.

"Sure!" cried Lance. "So many fathoms from a certain tree with arms like
a gibbet, on a line with a stone on which is scratched the outline of a
skull. Then dig straight down--so far--till you strike----"

"A lard kettle!" cried Jess. "Sounds just like Poe, doesn't it?"

"Just like Poe's ravin'," chuckled Bobby, the only one who dared make
such an atrocious pun.

They piled out of the boats at the usual landing and Billy took them to
the several "hide-outs," or camps, he had found while he was living like
a castaway on the island.

The twins were as eager to see Billy's camps as anyone; the big boulder
before the mouth of the farther cavern, into which they did not dare to
venture without a guide, had been the boy's lookout. That was where he
was perched in his wig and whiskers when Dora and Dorothy had first seen
him and nicknamed him "the lone pirate."

"And how under the sun did you chance to have that Hallow E'en disguise
with you, Billy boy?" demanded Dora.

Short and Long grinned. "I didn't know but one of those fresh detectives
was hanging around the house when I went off fishing that morning; so I
put on the wig and whiskers before I slid down the woodshed roof."

"By jolly!" laughed Lance. "You must have looked like a gnome when you
went through the streets."

"Nobody saw me. It was before sun-up," s