THE MEDUS.i:. 185 



Both in actual numbers and in frequency of occurrence, the Medusae as a whole were 

 most plentiful at about 50-100 fathoms, scarcest at the surface. 



Atolla bairdii, Fewkes. 



Out of the sixteen captures recorded for this species, fourteen were in deep water with 

 open nets, and are therefore practically useless for the determination of either the depth 

 or of the temperature-limits. One was taken at the surface, apparently just in the cold- 

 water belt of the Eastern United States, one by the ' Princesse Alice ' in 1905 with the 

 Giesbrecht closing-net at about 928 fathoms, and somewhere about 42°'8 E. The capture 

 in haul 30 a shows a temperature between 37° and 46° E. (2°-7 to 7°-7 C). 



The following table exhibits the distribution of the captures, by hauls and depths. 

 The first three hauls were made with the closing " mesoplankton trawl." 



