Notes on Meduscc of the U'cstcru Atlantic. 141 



and were found on examination of the washings. The towings were made 

 just before sunset. The moat was visited next day, and careful search 

 failed to bring to light any specimens. A mass of the filamentous alga was 

 pulled up from the bottom and put into a separate jar. The water in the 

 jar was soon observed to contain several of the minute medusae, but great 

 was my surprise to find, after returning to the laboratory and allowing the 

 jar to stand for a short time, not a few individuals only, but nearly a hun- 

 dred in various attitudes on the surface of the glass or amongst the weed. 

 The exquisite appearance of the delicate creatures, their tentacles fully 

 extended and interlacing at the tips, was most striking. Examined with a 

 lens, the tiny bubble-like bell was seen to stand upright, sturdily braced 

 upon the stocky pillars of the tentacles, which spread out at an angle with 

 the perpendicular so as to give an absurdly stable foundation to this frail 

 body. At the base of each tentacle a speck of color was displayed, the 

 ocellus, red-brown in hue. Exquisitely slender threads extended out radially 

 from the tips of the tentacles, each one branching into several similar 

 threads, and all strung at intervals with glistening beads of nettling cells. 

 These little organisms reminded one of nothing so much as the finest frost 

 tracery. 1 



Swimming reactions. And yet, this diaphanous delicacy of appearance 

 is coupled with remarkable activity when the creature releases its hold 

 upon its foundation and sets out to swim. It is only when disturbed, or 

 when the light conditions effect a stimulus which is transmitted from the 

 eye-spots to the nervous system of the medusa that the swimming reactions 

 are to be observed. The most of the time the creature holds fast to its place 

 in the weed, the long slender manubrium swaying about, apparently in 

 search of food. The behavior of Cladonema suggests that of Gonioncinus 

 in many respects, and one of these is the habit of reacting to the light- 

 stimulus, or to some impulse of a kindred nature, and going through a series 

 of vigorous swimming reactions for a longer or shorter period in the morn- 

 ing and at dusk. It seems to require an extra effort on the part of Clado- 

 nema to break loose from its moorings and set out upon its periodic quest for 

 food. The cause of this apparent inertia may possibly be the unusual 

 heaviness of the apparently frail body. 



When setting off, the jelly-fish makes one or two spasmodic attempts to 

 pull itself away, then suddenly shoots off at a great rate, sometimes leaving 

 behind a speck of tissue from one of the adhesive processes. The tentacles. 



1 The delicacy and vigorous activity of Cladonema are well portrayed by Van 

 Beneden (1866, Rech. sur la Faune litt. de Belg. : Polypes) : " Rien n'est gracieux comme 

 un Cladoneme nonchalamment etale an milieu de son bassin, fuyant devant quelque 

 danger imaginaire ou reel, ou solidement tapi par ses ventouses pour resister au 

 cpurant, pendant qu'il etale soigneusement ses longs cirrhes dans toutes les direc- 

 tions. On pent rester des heures entieres en contemplation devant ces organismes 

 infimes, qui semblent moins solides qu'une bulk de savon. et qui se conservent cependent 

 en depit des vagues, des chocs et des tempetes." 



