98 MADRAS FISHERIES BULLETIN [VOL. XVI, 



The weight of three typical oysters from the fishery held on 

 the Muttuvaratu Par in 1891 is 5*375 ounces, equivalent to a weight 

 of 17*916 ounces per 10 pairs of shells when the oysters were 

 approximately 6Y 2 years old. 



The annual increase in weight of oysters on the Tolayiram Par 

 compares, as will be seen from the above, very unfavourably with 

 the comparatively stunted oysters characteristic of the Western 

 Cheval. The nearest approximation was at the age of \Y\ years 

 when 10 Tolayiram Par oysters weighing 6% ounces were but 

 l/i ounce less than the weight of a similar number from the North- 

 western Cheval. During the next twelve months, however, the 

 latter gained 4% ounces as against an increase of 1% ounce by the 

 former. This disparity continued to increase more slowly there- 

 after, but unfortunately for want of data we cannot give the exact 

 amount for the age of /\Y\ years. 



It is a pity that we have not available a record of the yearly 

 weight increase of the oysters fished on the Ceylon Muttuvaratu 

 Par in the same years as those of the Tolayiram Par. If we had, 

 I think we should find that there would be shown close approxima- 

 tion between the two ; the Muttuvaratu oysters of that generation 

 were markedly stunted and poor and the fishery of 1889 was 

 decided upon only after considerable hesitation. 



The only datum I possess is the weight given above of three 

 typical oysters from the 1891 fishery. This which is equivalent to 

 a weight of 17916 ounces for 10 shells at 6% years of age as 

 against 17*64 ounces for a similar number of 6% years old oysters 

 from the Tolayiram Par in 1890 indicates practical identity in 

 growth-rate. 



By the courtesy of Captain Carlyon I have been enabled to 

 measure a few individuals of this last fished generation of Tolayi- 

 ram Par oysters and append a table thereof in which the measure- 

 ments of some of the oysters from the Muttuvaratu Par are included 

 for the sake of comparison. The numbers are too restricted to give 

 an average that may be taken as thoroughly trustworthy. They 

 constitute, however, the only data available and till systematic 

 records extending over a considerable series of years be obtained 

 by work in the future it is well to place them on record. 



