27 



during the period of fresliet in the early part of the season. 

 On many occasions no diatoms were found in the water, while 

 the stomachs of oysters taken at the same time as the sample 

 of water, contained only the empty valves of diatoms and only 

 a small number of these. The oysters on the jetties and those 

 found on the buoy in the gulf, had a much more abundant food 

 supjily during this season, and the result was evidenced in their 

 superior condition. In ]\Iarch and April of the present year 

 the conditions prevailing in the pass and gulf were such as may 

 h- considered normal for these waters, so that satisfactory 

 determinations of the food supply could be made. The food 

 of oysters in these waters, as is also true for other parts of the 

 State where I have had opportunity to make examinations, is 

 made up cliiefly of five species of diatoms. These are in the 

 order of their abundance: Coccinodiscus perforatus (sp?), 

 Eupodiscus radiatus, Melorsira sp., Navicula sp., and Pleuro- 

 sigma spenceri. The first mentioned form was, with few excep- 

 tions, by far the most abundant, and sometimes constituted 

 almost the entire stomach contents of the oysters. 



FOOD RECORDS. 



The food contents of the Avater and the number of diatoms 

 in the stomachs of the oysters were determiL,ed in the usual 

 manner by use of the rafter cell. One litre of water and the 

 stomach contents of three medium sized oysters being used for 

 each determination. 



TABLE NO. 6. 



Date. Source of oyster Diatoms in one Diatoms 



and Avater litre of'Avater. 



May 10, U5, "Light House" reef 100. 



May 15, '05 "Light House" reef 0.0 



May 20, '05, "Light House" reef.... 1,728. 



May 25, '05, "Light House" reef 3,297. 



June 8, '05, "Light House" reef 19.345. 



June 15, '05, "Light House" reef 16,628. 



June 22, '05, "Light House" reef 13,728. 



