"Nothing but X-plosive bullets," he growled in disgust, and in helpless silence the four watched an unspeakably hideous monster slowly appear from behind the Skylark. Its four huge, squat legs supported a body at least a hundred feet long, pursy and ungainly; at the extremity of a long and sinuous neck a comparatively small head seemed composed entirely of a cavernous mouth armed with row upon row of carnivorous teeth. Dorothy gasped with terror and both girls shrank closer to the two men, who maintained a baffled silence as the huge beast passed his revolting head along the hull of the vessel. "I dare not shoot, Martin," Seaton whispered, "it would wreck the bus. Have you got any solid bullets?" "No. We must hide behind these small ledges until it goes away," answered Crane, his eyes upon Margaret's colorless face. "You two hide behind that one, we will take this one." "Oh, well, it's nothing to worry about, anyway. We can kill him as soon as he gets far enough away from the boat," said Seaton as, with Dorothy clinging to him, he dropped behind one of the ledges. Margaret, her staring eyes fixed upon the monster, remained standing until Crane touched her gently and drew her down beside him. "He will go away soon," his even voice assured her. "We are in no danger." In spite of their predicament, a feeling of happiness flowed through Crane's whole being as he crouched beside the wall of metal with one arm protectingly around Margaret, and he longed to protect her through life as he was protecting her then. Accustomed as he was to dangerous situations, he felt no fear. He felt only a great tenderness for the girl by his side, who had ceased trembling but was still staring wide-eyed at the monster through a crevice. "Scared, Peggy?" he whispered. "Not now, Martin, but if you weren't here I would die of fright." At this reply his arm tightened involuntarily, but he forced it to relax. "It will not be long," he promised himself silently, "until she is back at home among her friends, and then...." There came the crack of a rifle from the Skylark. There was an awful roar from the dinosaur, which was quickly silenced by a stream of machine-gun bullets. "Blackie's on the job--let's go!" cried Seaton, and they raced up the slope. Making a detour to avoid the writhing and mutilated mass they plunged through the opening door. DuQuesne shut it behind them and in overwhelming relief, the adventurers huddled together as from the wilderness without there arose an appalling tumult. * * * * *