NEREIDIFORMIA 



315 



those of other Polychaetes. The prostomium has five tentacles ; 

 there are long peristomial cirri, and in general their anatomy 

 agrees most closely with that of Phyllodocids. Alciope, Asterope, 

 Vanadis, Nauphanta are genera of the family ; J none have been 

 recorded from the British area. 



FAM. 5. Tomopteridae.' This includes but one genus, Tom- 

 opteris, which is pelagic. The transparent, colourless body 

 consists of only a few (eighteen to twenty) segments; the 

 parapodia are as long as the body is wide, and carry no chaetae ; 

 each is bilobed, and fringed with a membrane ; each of these lobes 



a. 167. Tomop- 

 teris rolasi Grf. x 

 10. From Guinea 

 Isles, pr, Ham- 

 mer-shaped pro- 

 stomium ; x, first 

 chaetigerous pro- 

 cess ; y, second 

 chaetigerous pro- 

 cess ; c, rosette 

 (photogenic) 

 organ on first two 

 parapodia ; b, 

 similar organ in 

 the lobes of the 

 following para- 

 podia ; d, pigment 

 spots ; /, para- 

 podium. (From 

 Greef.) 



contains a yellow rosette-shaped photogenic organ. The only 

 chaetae present in the worm are on the " head." The prostomium 

 is hammer-shaped, and appears to carry a pair of short filaments 

 ventrally (Fig. 167, x), each with a single chaeta within it ; and 

 a longer filament laterally (y}, supported by a long, very delicate 

 chaeta. The mouth is behind these, and they probably are the 

 first pair of parapodia which have shifted forwards. T. onisci- 

 formis Eschscholtz is not unfrequently obtained off our shores in 

 the tow-net. 



FAM. 6. Nereidae (Lycoridae). This family contains a very 

 large number of species, differing from one another in small and 

 not readily recognisable characters, such as the relative lengths 



1 Greef, Acta Ac. German., xxxix. 1877. 

 Greef, Zcitsckr. /. u-iss. Zod. xlii. 1885, M. 432. 



