54 THE HALL OF SHELLS. 
“The whole Medusw family are very curi- 
ous and interesting, but none more so than the 
Physalia—our acquaintance of to-day,” con- 
tinued the doctor, losing no opportunity of 
instructing the children, who were delighted 
with the tales he told then. “Instances of the 
stinging powers of this inoffensive-looking crea- 
ture are given, which show that Tom may con- 
gratulate himself that he was prompt i obey- 
ing orders. There is a story told of a young 
sailor who, attracted as Tom was by the beauty 
of this jellyfish, sprang into the sea to capture 
it as it passed near the ship. When he reached 
it the creature entangled him in its threadlike 
filaments; in an agony of pain he cried for help 
and had barely been drawn on to the vessel 
when the intensity of the inflammation pro- 
duced by the stings of these tentacles occa- 
sioned brain fever. 
“The different members of this family in- 
habit all seas. Some of them are very large, 
reaching to. two feet across the disk, with their 
tentacular appendages extending like threads 
of many colors; others of diminutive size float 
in immense shoals, and with their phospho- 
rescence illumine the sea till every wave is ‘a 
flash of golden fire. There seems no end to 
the number and variety of these brilliant little 
. el de util : 
