FAUNISTIC RESULTS. 



439 



The great majority of the shallow-water forms have spread all round the island. 

 To take the pearl oyster as an index, while its home may be said to be the Gulf of 

 Manaar, it occurs in fair quantity in shallow water at Trincomalee, and sparingly at 

 Galle. In regard to the rarer and finer things, such as Solitary Corals, branched 

 Aleyonaria, Antipatharia, and some Echinoderms, Crustacea and Mollusca, I am 

 inclined to think the distribution is a question of depth rather than locality. They 

 have been found at Trincomalee and off Galle where rather deeper water was obtained, 

 but probably occur also in the depths outside the pearl bank plateau in the Gulf of 

 Manaar. 



Let us now pass the various groups in review so as to ascertain the general 

 impression given by the fauna in each case ; and I desire here to acknowledge that, 

 while I am alone responsible for any opinions that are not quoted from others, I am 

 indebted directly or indirectly to my friends the authors of the special Reports for 

 most of the facts upon which these opinions are founded. 



The Foraminifera figure largely in the deposits round the Ceylon coast. Two 

 extreme examples may be given. At the 100-fathom line, south of Galle, the bottom 

 seems to be practically composed of masses of the new species Ramulina herdmani, 

 Dakin ; and at several points in the Gulf of Manaar up to 40 per cent, of the deposit 

 is formed of Heterosteyinu depr'essa. Other species, such as Arryphistegina lessoni, 

 Orbitolites marginalis, and Alveolina melo, are also so abundant that to the eye the 

 deposit, when it comes up in the dredge, appears to be formed mainly of Foraminifera. 

 Polytrema miniaceum is also of very frequent occurrence, and grows to a large size. 



