OYSTER BEDS OF JAMES RIVER, VIRGINIA. 13 



experience in such work is such as insured their accuracy both as 

 to the area covered by the tonger and the quantity of oysters 

 taken. The oysters brought in by the biological party were all 

 examined by the author, who has also personally made all of . the 

 many calculations required and directly supervised the laying off 

 of the areas on the charts. The basis for the determination of the 

 character of the beds was decided on in advance, but the work of 

 the survey was so planned that it was impossible for any member 

 of the party to form an opinion as to the conditions found until 

 after the field work was completed, and any involuntary prejudice 

 was thus eliminated as far as possible. The author himself could 

 form but a vague idea of the general results until the charts were 

 completed and the report almost written. 



In the following pages the subject is gradually developed from a 

 detailed description of the several parts of the individual natural 

 rocks to a broad consideration of the market oyster and seed areas 

 as a whole, and in every case there is given the principal data on 

 which the several statements are based. 



OYSTER ROCKS. 



The term " oyster rock," as used in Virginia and employed in this 

 report, is synonymous with natural oyster bed and is to be distin- 

 guished from the term " public ground, " which is used to designate 

 the areas legally embraced within surveyed lines and set apart for 

 the use of the public. The public grounds were intended to embrace 

 all of the oyster rocks, and usually each includes a number of the 

 latter within its confines. 



An oyster rock is usually a more or less definite area of bottom, 

 limited by the extent of actual oyster growth. Originally, the bound- 

 aries were rather definitely marked and the rocks were separated from 

 one another by barren areas, but the operations of oystering have in 

 many cases strewn oysters and shells over the surrounding bottom, 

 so that in cases the original limits have become obscured and adjacent 

 rocks merged. 



On the accompanying chart much of the bottom indicated as 

 depleted really represents the areas which have been thus covered 

 with scattered oysters and shells, and the term employed indicates 

 that oysters and shells are very scarce rather than that they have been 

 removed, though the latter is the fact in many cases. The so-called 

 " depleted " areas are those on which oysters grow in quantities much 

 below those which would make it commercially profitable to tong 

 for them. 



The boundaries of the rocks, as shown by the red inclosing linos 

 on the charts and as considered in the text, were defined by the 



