1 8 MOORE. 



the fifth formed a cyst. Every stage of the process was 

 watched. The animal became perfectly quiet, and a clear 

 secretion was given off. After a time, probably from a sense 

 of discomfort, it moved away from this secretion, leaving 

 behind it an impression of its form. These impressions had 

 been seen before, but it was not known to what they were 

 due. After moving, the animal continued to give off the 

 secretion, and at the end of the next day the capsule was com- 

 pleted, the whole process taking three days. The other indi- 

 viduals began to secrete in the same way, but in one case the 

 animal was disturbed and the process stopped, and in the others 

 they were attacked by protozoa, causing disintegration. The 

 largest cyst that was found measured .5 mm., the smallest .13 

 mm. This decrease in size might easily account for their being 

 overlooked, but in addition to this it was found that after keep- 

 ing the cyst for a time the color faded out so that it became 

 practically unrecognizable. 



It is quite probable that this cyst is formed through the 

 activity of numerous gland cells in the skin. Many observers 

 have noted these glands, but no one has suggested an adequate 

 function for them. 



The affinities of Dinophilus and its systematic position make 

 it a peculiarly interesting form, and I hope in a more favorable 

 year to obtain sufficient material to complete my work upon it. 



THE MARINE BIOLOGICAL LABORATORY, 

 WOODS ROLL, AUG. 6, 1899. 



