St. Andrews Marine Laboratory. 175 



no grou|» is more eagerly tollowcd by the fishes than the 

 marine Annelids. 



As in eertain groups the spawning-period of the Annelids 

 is considerably prolonged (though not necessarily in indi- 

 viduals), that is, larvaj of the same species are found during 

 several months, a constant succession of young forms taking 

 the place of those which have advanced to the later stages 

 after undergoing changes more or less noteworthy, and many 

 of which settle on new sites on the bottom or amidst the rocks 

 to form i'resh colonies. A large number of these young- 

 stages are caught near the bottom by the trawl-like tow-net*, 

 and they are only occasionally to be found near the surface 

 under favourable conditions of temperature and the sea itself. 



The great larval bristles so characteristic of the young of 

 the Spionidaj do not seem to prevent in all cases their being 

 eaten by young fishes, though the observations are as yet too 

 few to enable definite conclusions to be made on this point. 

 These long bristles, however, may constitute an effectual guard 

 from the attacks of the smaller predatory Invertebrates, which 

 otherwise would prey on them. They certainly form a 

 striking fringe in the early stages, and the metallic lustre in 

 some species gives them no little beauty. 



Tonwpteris, formerly considered somewhat rare, is a form 

 which frequents the inshore waters from January to December. 

 The enormous numbers of the Chsetognaths again almost 

 throughout the entire year is a feature of moment in connexion 

 with the food of fishes, which readily devour them. In some 

 inshore areas the bag of the large midwater-net, after a brief 

 haul in autumn, is distended with a semisolid mass of them. 



The activity of the post- larval Annelids is great. They 

 glide rapidly through the water and often circle nimbly in a 

 limited area and again shoot towards the side of the vessel 

 next the light, where they collect like the Copepoda. They 

 are also voracious ; for instance, a post-larval Nerine [cirra- 

 tulus?) seized on the tail of a Scolecohpis a little less than 

 itself, and it was only after a severe struggle, in which botii 

 exerted themselves desperately, that the latter managed to 

 withdraw its tail — now considerably injured — from the eager 

 mouth of the Nerine. 



In the begitming of January various marine Annelids 

 present symptoms of maturity, such as the Polynoidse and 



* As formerly mentioned this net is invaluable in such investigations, 

 bringing to light, for instance, such forms as Ayahnopsis and Hybocodon, 

 which otherwise would have escaped notice. 



13* 



