72 THE STORY OF ANIMAL LIFE 



These last are again subdivided into the fol- 

 lowing : The Archiannelida or Primitive Annelids, 

 some of which have a curious ciliated larva, al- 

 ready referred to (p. 42) as the typical Trocho- 

 sphere or Wheel-ball ; the Oligochaeta (Few- 

 Bristles), which include the familiar earthworms; 

 and the Polychseta (Many-Bristles). Of the latter, 

 some, the Tubicola, live in tubes which may or 

 may not be fixed to some object ; while others, 

 the Errantia, or Wanderers, are free and very 

 active. Nereis, the Rainbow Worm (p. 159) may 

 be named as an example. Our illustration shows 

 instances of each group. A is the Sea-Mouse, a 

 bristly creature so named by some very imagi- 

 native person. It has two kinds of bristles, long 

 and short, the former being possessed of a peculiar 

 lustre (see p. 73). C is Syllis, one of a very 

 curious family of worms. In both A and C are 

 seen a row of paired appendages ; these are not 

 " legs," but expansions called " parapodia " which 

 serve the purpose of legs, besides which they fre- 

 quently act as breathing organs, a special part 

 being appropriated to this purpose. Each of these 

 animals is active and carnivorous, and has a head. 

 The Syllidae are remarkable for the very peculiar 

 way in which they divide, new individuals being 

 formed and cast off from the end of the body. 

 There is, however, a deep-sea form of Syllis which 

 divides in a very odd manner, giving rise to new 

 individuals placed transversely. The result is a 

 most extraordinary looking creature, a network 

 of worms with numerous heads, each branch being 

 eventually provided with one of its own. 



The tube-dwelling worms are represented in 

 our picture by Terebella, Serpula and Spirorbis, 

 ail very common forms on the English coasts. 



