9 



tin. ..uonnt Un- ..u-li nvstrr. Wl...,. Ih. ru.ul valu- of wnt.-. 

 „vrr ;i iK.nvn aiv;. was to be ai'trnnin.'.l. a nuinlMT ..I oysters 

 were transferred to that plaee. and aftrr l.avin- l-em left there 

 four days, were taken up and ihcMr slomarh contents exannned 

 in Ihe usual manner. The sample of water was allowed to stand 

 luitil all of the sediment and organisms, exeept actively swim- 

 uiinu' forms, had settled and formed a definite layer on the 

 bottom of the bottle. The water was now sii)honed otf to as 

 low a level as possible without dis1ui-l)ing the settlings. The 

 venmining water and sHtlings weiv. after being vigorously 

 shaken, transferred to a small graduated bottle and allowed to 

 settle. 



After a seeond siphoning away of the watei-, the contents 

 of the bottle, which now had a volume of either teu or lifteen 

 cubic eentimetei-s, were shaken up and one cubic centimeter 

 Avas iaken off for a determination of its food contents. The 

 diatom emud was i-epeated twice and an average of the three 

 determinations taken, the niunber of diatoms of the same 

 species as those found in the stonmch of oysters from the sam--' 

 locality being given as the food value of the water. In all de- 

 tei-minations of the food value of water, and the contents of 

 the oysters' stonuichs/ the number of the smaller forms of 

 diatoms have been left out of account, since it has been deter- 

 mined that by counting the larger forms only can we get as 

 cU-cui-ate a measure of the amouid of available food material .. • 

 ■we could if all foi-ms were included' in th(^ count. 



The character of the bottom was detei-mined by the use of 

 a sounding pole. Intersecting lines of soundings were made at 

 •short distances apart so that each area was thoroughly gone 

 over. In dejei'mining the exterd of the natural reefs the method 

 f)f running intersecting lines of time soundings was used, and 

 points on the borders of the reef were located by compass bear 

 ings from chai-fered points. 



The condition of the nalni-al reefs was determined by tong- 

 ing oystei-s fnmi several pai-ts of each reef and makinjx a carefi;' 

 count of the oysters, spat, dead shells, and aninuds living wilh 

 th.' o>-sters. 



The Natural Oyster P)eds of Vermilion and Iberia Pai-ish(>s; 

 Oeuei-a] Description of the TJegion — The area in which these 







uv 



