“You probably will, and meantime, in the morning we’ll hustle over to the place of your discovery and find out what it is that you’ve really got.” “I hope it’s the one you want—the Eotherium!” “If you found the bones on this level, it’s not,” rejoined the leader, “you can make your mind easy about that. A dead Eotherium wouldn’t work its bones up through a hundred feet of rock. But if you want to go with us in the morning to help prepare this specimen of yours, you’d better make a bee-line for your pillow now, for there’s a long day’s travel to-morrow and I won’t delay the start of the caravan for a dozen Eosirens. Sunrise for you, Perry, if you want to come.” “All right,” the boy replied, and being tired and backsore from the camel-riding, he started off for the sleeping-tent and was soon fast asleep. He had no difficulty in waking. The sense of expectancy brought him out of the tent even before the rim of the sun was above the horizon, and the dawn brought vividly back to him the vigil he had spent before the Sphinx. Early as he was, he was no more prompt than his uncle and Antoine, and in a few minutes the party was off, followed by a couple of laborers with shovels and one fellow carrying plaster-of-paris, canvas, and glue. The white handkerchief, spread out on the little cairn of stones, made a conspicuous object, and no time was lost in reaching it. To the trained eye of the professor, the tangled heap of bones contained no mystery. He gave them just one glance. “You’re right, Antoine,” was all he said, “it’s _Eosiren Andrewsii_.” Under the scientist’s expert directions, the laborers were set at work. Almost every movement of the shovels was watched with closest attention, and Perry was surprised at the extreme care that was taken. At last the bones were fully uncovered and Antoine made a detailed drawing of the exact position in which they lay. “How could you tell at once that it was a certain species of Eosiren, Uncle George?” asked Perry, while Antoine was busy with his sketch-block. “One gets accustomed to fossils, my boy,” was the reply, “and can tell a great many of them almost at sight. Then, Perry, any time that you want to try and determine for yourself what fossil bones may be, remember that there are only a certain number of animals which they can possibly be. You know from the stratum, for example, that the bones are not likely to be those of a creature which developed in later times, nor of one belonging to an earlier stage of development. You’ll see just what I mean if I say that you couldn’t find a Pteranodon in this stratum because all the Pteranodons were dead before this layer of rocks was laid down. “But I thought Sirens were sea-cows, things like the manatee and dugong,” protested the boy. “They are,” said the scientist, “what about it?” “This beast has got four legs.” The professor nodded approvingly at his nephew.