78 



LIFE BY THE SEASHORE. 



likely to be found on the West than on the East Coast, 

 and in any case are somewhat beyond our scope. There is a 

 small, delicate creature, however, to be found on the rocks 

 which is related to the jelly-fish, though it differs from 

 them markedly in appearance. This is Lucenaria, or as it 

 is now called, Halidystus odoradiatus. It is, perhaps, 



rather umbrella -shaped 

 than bell -shaped, but 

 there is nothing to re- 

 present the stick of the 

 umbrella that is, no 

 manubrium and the 

 region of the body oppo- 

 site the mouth is pro- 

 longed into a short stalk 

 which is attached to 

 weed in the pools. The 

 free margin of the um- 

 brella bears eight groups 

 of short tentacles, and 

 the mouth has the usual 

 central position. It is 

 an animal which is diffi- 

 cult to find, though perhaps it is not very uncommon, and 

 reaches a size of one inch or so. The difficulty is largely 

 due to its delicacy and transparency, and to the fact that 

 in colour it usually resembles the weed to which it is 

 attached. It shows no trace of alternation of generations, 

 and is interesting on account of a certain general resem- 

 blance to a hydra-tuba, so that one might suppose that it 

 was a larval jelly-fish which had forgotten to grow up, and 

 had become adapted for a sedentary life. It is not a 

 perfectly stationary form, but possesses some power of 

 moving about, and by attaching itself, first by the stalk 

 and then by little marginal tubercles which alternate with 

 the tentacles, can progress like a "looping caterpillar." It 

 is a charming little creature, but, so far as my experience 

 goes, not easy to keep in confinement. The colour is very 

 variable, being brown, green, or claret-coloured, according 

 to the colour of the surrounding weed. The accompanying 

 figure should make the structure obvious. 



Fia. 27. Halidystus octoradiatus. 



