100 CEYLON PEARL OYSTER REPORT. 



sand, diversified here and there by cmtcrops of so-called " rock," generally in the form 

 of flat or slightly-inclined ledges, sometimes stepped to form low terraces, sometimes 

 level with the surface, and sometimes even a few inches under it, the rock being then 

 covered by a thin layer of sand, which shifts from time to time with the currents. 



Some of the paars, such as the Muttuvaratu, Karativo, Dutch Modragam, and 

 parts of the Western Cheval, are formed almost entirely of rock, and the small amount 

 of sand found in crevices and sprinkled over parts is mostly of organic origin 

 He'erostegina, Alveolina, Orbitolites, and other large Foraminifera and fragments of 

 shells. On other paars, such as the East and South Cheval, angular quartz sand 

 predominates, sometimes underlaid by flat rock which crops out at intervals. Mr. J. 

 Lomas, F.G.S., who has examined the samples of " rock " we obtained from the 

 paars, is of opinion that they are all of recent origin, and are in fact merely a 

 consolidation or cementing of the sand in situ. Further details of the nature of these 

 modern calcareous rocks or " Calcretes," and of their mode of formation on the paars, 

 will be given in Mr. Lomas' report which follows. 



The calcretes naturally vary considerably from place to place, being in some cases 

 mainly composed of terrigenous materials and in others being mainly neritic or 

 formed of organic remains. The rock may be a grit stone formed of the yellow-tinted 

 quartz sand, which is so abundant, cemented by carbonate of lime, or it may be largely 

 dead worn and altered coral, or it may be a shelly mass, an agglomerate of the dead 

 valves of pearl-oysters, cockles, and Pectunculids with Nullipores (Lithotha/mnion) 

 and Polyzoa (Lepralids) intermingled. 



In addition to the paars described below, there are a few others, marked on the 

 chart as " Old " or "Old Dutch" (see figs. 28 and ?>7), which are either erroneous 

 positions of other paars now more accurately determined or are patches which formerly 

 bore oysters and have since changed their character. 



We must not, however, try to be too precise in regard to the positions, sizes, and 

 outlines of the paars. Our work in the "Lady Havelock " showed us that some 

 spots around and between them are more or less hard-bottomed, and even in some 

 cases bore oysters and are capable of becoming paars. On the other hand, it is 

 known from the inspections that many parts of the known jsaars are temporarily, and 

 possibly some parts even permanently, unsuitable for the attachment or rearing of 

 oysters. We may consider, then, the whole plateau as potentially " paar " ground 

 some parts of it better suited for one purpose and some for another, some parts more 

 constantly covered by the shifting sands, others more regularly bare and hard. This 

 renders possible the farming operations, such as " culching " and transplanting, which 

 we discuss in our " Recommendations." 



Cheval Paar. 



This is the most important and the largest of the paars, and is the central member 

 of the northern set, most of the other paars being grouped around it (see fig. 28). 



