CLASSIFIED RESUME OF ORGANISMS OBSERVED 297 



exactly balanced to sustain its load at just the right level. 

 The chains of polyps trailed behind for sometimes a full 

 yard. The light was almost always pale yellow. In the 

 majority of cases, however, no illumination was apparent 

 and the colonies were visible only when they entered our 

 beam. 



In the plankton of the trawling nets the nectophores of 

 Calyconid siphonophores are abundant, but we have taken 

 the more highly organized forms in only the fragmentary 

 condition. A few broken and distorted nectophores and 

 several ragged bits of other polyps are the only traces of 

 their presence in the water. 



Classes hydrozoa and scyphozoa 



Medusae were among the commonest of all the organ- 

 isms observed. They were reported altogether seventy-nine 

 times, from 20 to 2750 feet, but were actually seen on 

 many other occasions and at all depths. The majority were 

 noticed above 1000 feet. This, however, does not necessa- 

 rily indicate that they are less common at lower levels, be- 

 cause, as relatively few forms are luminous, these are in- 

 visible except when they enter the electric beam, or are 

 illumined by the light of other animals. 



Most of the jellies were small, measuring from one-half 

 to three or four inches in diameter. Large numbers were 

 pale and transparent, but pink-tinged aurelias were fairly 

 common in the upper levels, as well as brown linuches, 



