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PREFACE. 



The plan of this work is as follows : - 



An Introduction explaining briefly the past history of the Pearl Banks in the 

 Gulf of Manaar and the circumstances which led to my Ceylon Expedition, and the 

 subsequent work to which it gave rise, is followed by a section, entitled Narrative, 

 which deals with the course of the investigations undertaken by Mr. Hornell and 

 myself, given in chronological order. The observing stations where the fauna was 

 investigated around the Coast of < 'eylon are described in detail in the Narrative ; but 

 those other investigations such as the anatomy of the Pearl Oyster, a description of 

 its parasitic worms, and an account of its pearl-formation which will be dealt with 

 separately in special articles later on, are not treated fully in this section. After the 

 Narrative comes a Description of the physical condition of the pearl-oyster banks or 

 "paars" of the Gulf of Manaar, followed by their classification from the fisheries point 

 of view, and by a short discussion as to the causes of certain paars being unreliable, 

 and of the serious mortality of the oysters. Then comes a section dealing with the 

 Observations and Experiments made by Mr. Hornell and myself on the life-history 

 and habits of the pearl oyster, which form the basis of some of our recommendations 

 as to the cultivation of the oyster banks. 



This general part is then followed by the Supplementary or Special Reports, which 

 various scientific friends have kindly undertaken to write upon their special groups or 

 subjects. I feel that these articles by experts add very greatly to the completeness 

 and value of this Report, which without them could only have given a very 

 imperfect account of the fauna, and flora of the Gulf of Manaar and of the other 

 natural conditions of existence surrounding and influencing the pearl oyster on the 

 various " paars." 



Of these special Reports, seven are published in the present Part I. The first 

 of these is on the Geology of the Sea-bottom, by Mr. Joseph Lomas, F.G.S. ; it 

 deals with the very fundamental question of what the " paar " is, how the hard, 

 cemented material usually known (and marked on the charts) as " rock," which by 

 its presence enables the pearl oysters to live, there, comes to be formed. 



The next is by Mrs. Gepp on the Alg?e collected, and this contains an account of 

 the previously unknown fructification of a species of Halimeda, one of the commonest 

 and most characteristic forms of sea- weed on the pearl banks. 



