THE OTOCYST OF THE PINXID/E. \~J 



PHYSIOLOGY OF THE OTOCYST. 



While at Beaufort, North Carolina,' during the summer of 

 1911, the writer made a study of the function of the otocyst of 

 Atrina rigidia, but the experiments gave only negative results. 



A considerable number of specimens were brought into the 

 laboratory and kept under observation to learn their individual 

 behavior. They seemed to surfer no inconvenience after the 

 removal of the tip of the foot, which supposedly contained the 

 otocyst. The normal activities were continued after the opera- 

 tion as before. The following conclusions seem justifiable: 



First. A large per cent, of Pinnas have no otocyst. When one 

 is present, it is abnormally large and curiously pathological in 

 appearance. 



Second. Anatomical and physiological evidence seem to indi- 

 cate that the otocyst of the Pinnid^p is undergoing degeneration, 

 and is at present of no functional value. 



1 I wish to acknowledge my indebtedness to Hon. George M. Bowers for the use 

 of a table at the fisheries laboratory during my stay at Beaufort. 



