26 



varying from 2^ inch to 4 inches, the grades being 

 numbered as follows : — 



No. I shells over 4 inches diameter. 



The following table shows the average proportion of 

 shells of the different sizes fished in an average season, 

 1910-1 1, viz : — 



In addition to the above were : — 



22,316 undersized shells (under 2^ inches diameter) 

 . 12,952 wormed (of all sizes). 



The above gauges are adopted from the gradation of 

 gauge sizes employed by the Calcutta buyers in sorting 

 their shells; prior to 1910, this sorting of shells was not 

 practised by the Government staff, the 'shells being 

 divided into three lots only, (a) those above 2f inches 

 diameter, {/?) " medium " shells, below 2^^ inches diameter, 

 and (<;) wormed shells, and sold en bloc on these figures. 



Sorting into grades before sale enables purchasers to 

 assess the value of the shells with accuracy and is one of 

 the improvements introduced since the conduct of the 

 fishery passed into the hands of the Fisheries Depart- 

 ment. 



"Wormed" shells are those tunnelled by the laby- 

 rinths made by decalcifying burrowing sponges of the 

 genus Clione. The extent of infection varies "reatlv 

 from bed lo bed : usually it is greatest on the near shore 



