POLYPS 21 



anchored in the mud. The single Polyp may be 4 ft. long 

 with a 2-ft. spread of tentacles and is the subject of a weird 

 legend current among the native fishermen, namely that 

 it guards the bower of a beautiful sea-maiden. 



Next in order to the Hydroids are the Siphonophores. 

 Though commonly called Jellyfish, these are more complex 

 creatures than the true Jellyfishes found stranded on our 

 shore or the minute Jellyfishes of the Hydroids just 

 described. The Siphonophores appear to be individuals, 

 but are in fact colonies of many individuals. Some are 

 concerned only with the capture and digestion of food ; 

 others concentrate upon reproduction ; whilst others 

 again have formidable batteries of stinging cells which 

 kill or sting the prey and keep foes at a distance. Most 

 of these creatures carry a floating bladder filled with gas 

 which acts as a support in the water. 



The commonest of our home species is a small transparent 

 bell-shaped form having no other name than Muggiaea 

 atlantica. More startling are the forms popularly known 

 as the Sallee-rover and the Portuguese Man-of-war 

 semi-tropical forms which occasionally appear off Devon 

 and Cornwall in vast numbers. Each colony is supported 

 by a gas-filled bladder an inch or two across and of 

 a vivid indigo blue. Fleets of these creatures may form 

 long lines or platforms visible far out at sea and drift 

 helplessly before the wind. As they reach colder waters 

 they soon die and disintegrate, detached floats or bladders 

 sometimes surviving as far eastwards as the Sussex coast. 

 The float of a Portuguese Man-of-war carries a crest 

 which projects above the surface of the water and acts as 

 a sail. It may reach a foot in length, and is a most con- 



