352 



University of California Publications in Zoology [Vol.22 



1920) in investigations on teredos and other marine borers. It gives 

 approximately the proportion of ocean water in straits water, but 

 includes also the saline content of the stream and seepage water. Such 

 a standard may allow a small error when used as a measure of actual 

 physiological properties of sea water, particularly in Carquinez 



Fig. 1. Diagram of aquarium used in Teredo experiments. 

 A, wedge for holding specimen block. 



Straits where great amounts of river water are present during several 

 months of the year and various sources of industrial pollution are 

 probable. It serves as a convenient standard, however, and the actual 

 error is probably not greater than other experimental errors. All 

 references to salinities are based on this method of determination. 



The teredos used in the following experiments were obtained from 

 piles pulled from the docks of the Sugar Refinery at Crockett. This 

 form was determined as Teredo navalis by Kofoid (1921 and 1922). 



