Sometimes schools of little fish gliding beneath the dingy began to dash wildly about, and a moment later a group of jackfish or Spanish mackerel could be seen darting around and picking up stragglers from the little school, which often huddled for protection close beside and beneath the dingy.  Dick like all brave boys, was on the side of the under dog, and he laughed with glee when a quick-moving mackerel shark appeared among the pursuers of the little fish and picked up a few of them for his breakfast as he drove the rest away.  As Dick sculled easily with one hand, he kept an eye upon Pedro, and obeyed the signals of his hand, to go to the right, the left, or stop, as sponges were seen.  Then from time to time the long pole with the claw at the end was lowered to the bottom and a sponge torn loose.

Sometimes Dick changed places with Pedro, and manipulated the long pole with the claw, while Pedro handled the sculling oar.  Then Dick began to learn the difference between coarse grass and common cup sponges, and the finer fibred glove and choice sheep’s wool varieties.  For when he was clumsy with the pole, Pedro only swore softly in Spanish, but when he brought up a worthless grass sponge, the big oar was lifted, and the boy might have been knocked overboard but for the iron claw which he held high, while a purpose gleamed in his eye which made Pedro peaceful.  But Dick felt that Pedro was half right and he set to work studying sponges until he knew them almost as well as his teacher.  His strength and skill with the sponge hook were less than the Spaniard’s, but his eye was quicker and Pedro’s chronic growls were often changed to grunts of approval.  When the surface of the water was ruffled by a breeze it was needful to use the water-glass.  Then Pedro sat with his head in the bucket, studying the bottom, and when he took up the heavy pole which lay on the thwarts of the dingy and dipped it vertically in the water, it was the duty of Dick to stop sculling at once.  But once while Dick was sculling and looking for sponges he saw gliding beneath the dingy, a whip-ray, the most beautiful member of the ray family.  Shaped like a butterfly, its back is covered with small, light rings on a black background.  Its long, slim tail is like the lash of a coach-whip and at its base is a row of little spears with many barbs, which are capable of inflicting exceedingly painful wounds.  The roof of the mouth and the tongue of the fish are hard as ivory and shell-fish are ground between them as rock is pulverized by the jaws of a quartz-crusher.  As Billy watched the graceful swaying of the body of the whip-ray under the impulse of its wings, a wandering shark came upon it.  In its first rush the tiger of the sea almost caught the beautiful creature, which fluttered for a hundred yards upon the surface of the water, with the jaws of its pursuer opening and closing within a few inches of its body.