The Comb Jellies and Others 79 



a crystal dinner plate Indented at the margin with eight 

 notches. In each of these marginal notches, hidden by 

 a hood, Is a small tubercle containing the eyespot. A 

 very short cluster of tentacles fringes the circumference 

 of the animal. Four horseshoe-shaped sex organs ar- 

 ranged In a geometrical pattern around the center, well 

 within the body, are a conspicuous and ornamental fea- 

 ture. By their color, one can readily recognize the sex 

 of the Individual : In the male they are pink, and In the 

 female they are yellow. Aurella revels In the sunlight. 

 On cloudless days, when the water is smooth, It swims 

 near the surface, reflecting the most delicate hues Im- 

 aginable from Its purple-tinged tissues. 



In common with other jellyfishes, Aurella swims in 

 a very characteristic manner. Not being possessed of 

 swimming paddles, or cilia, like the comb jellies, its 

 mode of progression, quite obviously, differs from 

 theirs. In short, it propels itself, not by the aid of 

 organs adapted to this purpose, but by alternately con- 

 tracting and expanding its disk. The action is like 

 nothing so much as the partial closing and opening of 

 an umbrella. This jellyfish never rests. The rhythmic 

 movement of its body continues without intermission 

 throughout its adult life like the beating of the human 

 heart. 



No less remarkable for Its beauty is Cyanea fiilva. 

 This species may well be termed the "little brown 

 brother" of the more widely known C. arctica, or sea 

 blubber, the largest jellyfish in existence. Although 

 more local in its distribution than the latter, and dif- 

 fering from it In size and color, Its general appearance 

 and habits are otherwise about the same. In our 



