74 A NATURAL HISTORY OF THE SEAS 



Worms (Turbe liana), as they are called after the flattened 

 leaf-like forms and the whirling currents of water set up 

 by the lashing hairs with which they are covered. All 

 are predacious, feeding upon other worms, aquatic snails 

 and crustaceans. 



One of our commonest native species is the Living 

 Film Worm (Leptoplana tremellaris), common in summer 

 beneath stones, etc. It is transparent, leaf-like and about 

 half an inch long, moving rapidly by lateral movements 

 of its compressed margin in the manner of a skate. It 

 has well-formed eyes and a suctorial mouth on its under- 

 surface, and also the nucleus of a brain. Like many 

 worms, it seems happily indifferent to mutilation, detached 

 portions developing into separate worms ; it reproduces 

 by means of eggs. 



Allied to these simple unsegmented worms are the 

 Ribbon Worms {Nemertirii). The typical Ribbon Worm 

 has a brain, a nervous system, several groups of eyes, 

 and an elongate tubular proboscis. Most of our native 

 species are small, but there are a few striking forms which 

 arrest the attention of the most casual observer. The 

 foremost of these is a worm commonlv known as Bootlaces 



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or Living Fishing-line Worm (Lineus longissimus). As 

 disclosed beneath some upturned boulder it suggests a 

 mass of calves' liver. In a tank or pool this reveals itself 

 as a smooth silvery worm of apparently limitless dimensions. 

 Specimens of over 90 feet have been recorded, and when 

 such a worm has attached its bell-shaped mouth to a fish 

 the victim is literally played by this living line until it 

 succumbs to exhaution, and it is then slowly engulfed. 

 The Bootlace Worm reproduces very rapidly by division ; 



