EIIKANTIAÏE POLYCHAETA OF JAPAN. 59 



Habitat : — Near Shiiiagawa, in the Gulf of Tokyo (!). 



G onus Scalisetosus Mcintosh. 



Anterior border of prostomiuni smoothly rounded. Eyes 

 placed close together on each side, the two groups being widely 

 separated from each other and placed far back on prostomiuni. 

 Subtentacles smooth. Proboscis somewhat thin. Body of moderate 

 length. Scales cover dorsum in front, but posteriorly leave the 

 central part bare. Bristles colourless and transparent ; dorsal 

 bristles slightly curved, some or all of them l)earing vei-y distinct 

 spines. A" entrai bristles slender, elongate, with close spinous rows 

 and with hooked and bihd tip. 



Scalisetosus 2*aci ficus n. sp. 

 PL VII, figs. 1 — 7. 



The following description is based on a single specimen from 

 which some of the elytra had become detached. At the posterior 

 end is a small regenerating part, but the form of this region, 

 especially the structure of its parapodia, indicates that the w^orm 

 is [)ractically in normal length. 



The body, consisting of 33 segments besides the small re- 

 generating part of a slightly shorter length than the last two 

 normal segments taken together, measures K» inni. in length, 

 ;> mm. ill maximum breadth and 7 ]nm. including parapodia and 

 bristles ill ;il)()iii llir [-Jtli scgmciil, wlieiicc the Ijody tapers very 

 gr;iilii;illy lowaid tli(> posterior end, but more rapidly toward 

 the aiitoior. 



Porsiim [ijilc ycllowisli anteriorly, which colour gradually fades 



