ERPiANTlATE POLYCIIAETA OF JAPAN. 



Systematic. 

 Family Polynoidae. 



Body flattened, with nearly parallel sides ; usually short, more 

 rarely elongate. Prostomium with 2 — 3 tentacles and 4 eyes. 

 Peristomium with long dorsal and ventrai cirri ; ventral cirri of the 

 next following segment also elongate. Pharynx excertile ; jaws 

 present. Elytra usually in 12 — 18 pairs, sometimes numerous; 

 their surface more or less papillose, sometimes fringed with long 

 processes along the outer border. Colouring of elytra cliaracteristic 

 to most species, though liable to considerable variation in some cases. 

 Nephridia open ventrall}' on pa])illa near base of parapodia. 

 Bristles unjointed, generally strong, of a bright golden colour. 



Key to the genera found in Japan. 



n'. Tentacles 3. 



//. Anterior tip of prostomial lolies produced to form basal joints 

 of the paired tentacles. 

 (■'. Dorsal bristles nsnally present ; ventral bristles numerous 



Pdynoë. 



c". Dorsal bristles absent ; ventral bristles sparsely present 



Pohjnoëlla. 



II". Prostomium prolonged anteriorly into t-svo acuminate or rounded 

 peaks. 



c'. P>()t]i dorsal aiul ventral bristles serrated for a consider- 

 able ]iürtiou of their exposed leugth Harmothoë. 



c". Bristles colourless and quite transparent ; the dorsal 

 slightly curved, the ventral with rows of close set spines 



