CLASS ELASMOBRANCHII 343 



Linnaeus, also does serious damage by destroying nets, devouring 

 captured fish, stealing bait, and driving away or destroying schools 

 of squids used as bait. The damage done by these sharks to Massa- 

 chusetts fishermen alone has been estimated at not less than $400,000 

 per year. Sharks, however, have been made use of in various ways. 

 From them is secured an oil; the flesh which remains after the removal 

 of the oil is sold as a fertilizer; the skin has been tanned; and the flesh 

 itself has been canned and sold commercially under the name of grayfish. 



