ime of it the past few days, and the cave damp had set his tired limbs
to aching.

For upwards of an hour they followed dark and winding passageways, (rats
and lizards and occasional colonies of bats fleeing before them),
naturally without the slightest sign of the fugitives, when they came to
another grotto, the loveliest they had yet seen. It might have been a
fairy cavern, aglitter with pure crystal. The carved prisms shone
dazzlingly in the light of the carbide lamp, and the boys stuffed their
pockets with some of the jewel-like bits that had fallen to the floor.

From this they presently entered into what seemed like a Gothic
cathedral, with a dome whose highest point must have been several hundred
feet above. The boys were fairly awed by its beauty, while the Ranger's
eyes gleamed appreciatively. On the walls were what might have been
carvings of flowers and lacework, creamy to smoke color, gypsum, Ace told
them.

"Are these fossils?" demanded Ted excitedly.

"I should say not, you poor fish!--You ichthyosaurus," laughed Ace
teasingly.

"You what?" asked the Ranger.

"That means ancient fish."

"All right," grinned Ted. "If I'm an ich----"

"Ich-thy-o-saur-us?" Radcliffe came to his rescue.

"Then you're a dinosaur," grinned Ted.

"Here, here, stop calling each other names!" commanded Radcliffe. "And
perhaps Ace will tell us about this gypsum formation."

"Thunder! Wish Norris was here! I tell you I'm no professor. But if
you're after fossils, don't you remember what he told us, that day just
before we lost the pack burro?--That in this part of California we have
rock from the Cambrian era a mile thick, and I'll bet it's full of
fossils of the fish age!"

"Well," Radcliffe briskly interposed, as they came to another turn,
"we'll never find those Mexicans unless we separate and hunt faster than
we've been doing. Are you fellows game for taking one way while I go back
to that last turn and try the left hand passageway? Of course the instant
you get wind of them, report back to me." They signified their gameness
by picking a precarious footing, (Ted first), along the slippery floor,
their candles thrust in their hat bands.

Above they came to another but a smaller forest of alabaster stalactites,
shining like icicles or mosses, some white as snow, some yellow as gold,
and some so like maple sugar in appearance that Ace actually tasted it.
In one place there was a bit of what Ace said was needle gypsum