COASTLINES 



about six inches long in the Chesapeake Bay district, 

 ahhough it may be as long as ten inches in others. The 

 "gangster" with which it associates is the Al Capone of 

 all jelly-fish : that most fantastic many-individuals-in-one 

 creature so studiously avoided by swimmers and known 

 to mariners as the Portuguese man-of-war. 



This extraordinary creature (or, more exactly, colony 

 of creatures) belongs to that enormous group of life- 

 forms known as the Coelenterata, ranking next above the 

 sponges and their relatives in the ascending order of the 

 animal scale, yet contrasting strongly with them. The 

 creatures of the group are distinguished from those in 

 other groups by the fact that each individual has a central 

 digestive cavity, communicating with a system of canals, 

 while it has prehensile organs around its mouth. The 

 Coelenterata include corals, sea-firs, sea-pens, sea-anemones 

 and jelly-fish — to give but a brief and inadequate list. 

 The range of species within the group is vast and varied, 

 ranging from tiny animals scarcely visible to the naked 

 eye to monsters several feet across. 



There are innumerable soft-bodied forms in the 

 Coelenterata, composed almost entirely of water. There 

 are — at the other extreme — the reef-builders, almost a 

 hundred per cent limestone. There are species which 

 burrow in the mud and trail tentacles, and (again going 

 to the extreme) grotesque shapes like the Portuguese 

 man-of-war — gangster-like "protector" of the American 

 harvest-fish — ^floating on the surface and trailing their 

 tentacles a little below it. But whatever their form, nearly 

 all the Coelenterates — small, large, soft, hard, mud- 

 burrowing or surface-floating — possess nematocysts : 

 small stinging cells. 



There have been many philosophic mariners through 

 the centuries who have believed that every conceivable 

 device found on land has its counterpart somewhere in 

 the world's oceans, and writers of sea books have often 

 shown tendencies to agree with the "old salts" in their 



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