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THE AMEBIC AX X ATI' BALI ST [Vol. LII 



3,000 ft. or more. Tlie central lagoon is seldom more 

 than 60 ft. deep, and is often much less. There are 

 usually one or more navigable passages leading from the 

 lagoon to the open sea. 



The thickness of the Hawaiian reefs is an engaging 

 subject for speculation. Many of the reefs are undoubt- 

 edly several thousand feet thick at their seaward margins. 

 Dana writes : 



Could Ave raise one of these coral-bound islands from the waves, we 

 should find that the reefs stand upon submarine slopes, like massy struc- 

 tures of artificial masonry ; some forming a broad flat platform or shelf 



The late Dr. S. E. Bishop, of Honolulu, estimated the 

 depth of the coral at Barber's Point, Oahu, to be 2,500 ft. 



Our first exploration of a Hawaiian coral reef, some 

 ton years ago, made a lasting impression, so novel and 

 vivid were those initiatory experiences. The tropic 

 morning was fine and clear, with the clouds heaped along 

 the mountains, and the seaward sky flawless. The trade 

 winds were unusually quiet and the tide was at lowest ebb. 

 All conditions were most favorable for a detailed exam- 

 ination of the reef. My comrade and I embarked in a 

 native outrigger canoe and paddled from the well-known 

 Waikiki Beach, near Honolulu, to the white surf-lines of 

 the reef-rim. This is one of the richest portions of the 

 Oahu fringing reef, from the biological standpoint. We 

 were clad in bathing suits and provided with suitable col- 

 lecting apparatus and water-boxes— glass-bottomed boxes 

 by means of which the sunlit translucent waters are easily 



^ Arriving at a suitable location, a thousand feet from 



anchored the canoe and prepared for wading. We were 

 equipped with old shoes to protect our feet from the coral 

 (which can cause very painful and slow-healing wounds) ; 

 with broad-rimmed hats to protect eves, face, and neck 

 from the intense glare of sun and water; with hammers 



