THE EDGE OF THE EDGE 383 



below the rim and their progress was rather leisurely, inter- 

 rupted by all sorts of side excursions. 



Once I saw a barracuda. Long and slim and graceful, it 

 emerged from the filmy distance and came to a stop a few feet 

 away. Across its gill flap was a deep line which gave it a hard, 

 grim appearance. It eyed me coldly, hung motionless in the 

 water for about three minutes, and then without visible effort 

 slid away into the blue. I was not as nervous over the barracuda 

 as I had been over the devilfish, though I might have been, for 

 the barracuda are the reputed tigers of the sea. 



The greatest thrill came when a great green turtle, weigh- 

 ing a hundred pounds or more, swept by. It arrived from be- 

 hind me somewhere, sliding just above the sand, reaching out 

 with graceful motions of its flippers. It paid me not the slight- 

 est attention and went by within ten feet. Great masses of 

 whitish barnacles covered its shell, and it was adorned with a 

 filmy carpet of greenish moss. Like the manta it was carrying 

 a parasite, a remora attached to the underside of its shell. Hang- 

 ing close to the bottom, it slid over the edge and vanished in 

 the gloom. I could :fiot help wondering where it was going, 

 because I knew there was a limit to the time it could stay below. 

 Turtles breathe atmospheric air and must come to the surface 

 at regular intervals. But down it went, down into the hazy 

 distance and the dark. 



The turtle gave a clue to another type of migration on the 

 cliff edge, a migration that was not as important as the long 

 shore migration. Fish were gliding back and forth from the 

 depths and the shallows of the bank. The most abundant of 

 these were the squirrel-fish, which I had not seen in any large 

 numbers before except at night: A steady stream of them fil- 

 tered out of the depths. They seemed to know where they were 

 going and headed straight for the rocks on shore. Others were 

 returning, coming to the edge and slipping over and down. 



