PERILS OF THE OYSTER. 241 



number of the rough whelks (urosalpinx cinereus) than 

 during the previous season, and though they were not 

 found in as large numbers as the astyris, yet their presence 

 inclined me to question the conclusions arrived at during 

 the season of 1878. I accordingly collected a large num- 

 ber of astyris, and placed them in an aquarium jar with a 

 number of young oysters, changing the water constantly 

 and inspecting the animals frequently. The observations 

 were continued over a week, and at the end of that time 

 both oysters and astyris were alive, but there was no evi- 

 dence of any boring, nor did any inspection show an 

 inclination in that direction upon the part of the astyris ; 

 on the contrary, they soon left the shells and went to the 



j ' J 



bottom of the jar. I then collected a number of urosalpinx 

 cinereus, and subjected them to the same test. At the end 

 of four days one oyster had been bored, and one whelk 

 was found at work on the shell of another. The rough 

 whelk is known to do great injury to the oyster in Long 

 Island Sound, and the destruction of the young, alluded to 

 in my previous reports as due to the drills, may be effected 

 by this animal. That large numbers are destroyed by the 

 whelks cannot be doubted ; but as it is possible that the 

 astyris may also assist in this destruction, ^. more extended 

 investigation of this question than I was enabled to make 

 is desirable." 



