EKEANTIATE rOLYCHAETA OF JAPAN. 69 



unique spocimon dredged in Sagami Bay, 290 fathoms, on Aug. 

 17tli, 1903. 



]jody consists of 8() segments ; length 95 mm. ; maximum 

 Itrendth inckiding pai'apodia and setae, in the region of about the 

 20th segment, S mm. ; same in exckision of parapodia 5 mm. ; 

 maxinuim tliiekness 4 mm. 



Jn tlie specimen which is preserved in alcohol, the dorsal 

 surface in tlie anterior one-eighth of the body is brownisli, dis- 

 tinctly marked off laterally from light yellowish parapodia ; and 

 in tliis part of the dorsum there are seen very fine transverse 

 striations, which obscure the demarkation lines between segments. 

 Posteriorly the colour changes into light yellowish djrown and 

 finally into light-yellow near the posterior end of body, showing 

 liowever a brownisli median line traceable nearly to tlie posterior- 

 most end, indicating the course of the dorsal median blood vessel. 



The N'entrai surface is pale yellowish. In the median line of 

 this side there runs a, brownisli longitudinal band marking the 

 course of the ventral nerve chain. The band shows a slight con- 

 striction at eacli intersegmental position. Moreover, the band is 

 somewhat l)i'oadens anteriorly, and terminates abruptly just ix'hind 

 the mouth. 



I'rostomium (IM. A^ii, tig. I) lallen together with the omma- 

 f > i| tliorcs nboiil (\ as long as (lie snb(('nta<'l('s. Tlie ommatophores 

 arc anb-rior prolongal ions of t he prosbaninm. bearing on 1 i[) the large 

 roiiMil eve of a (|ee|) black coleur. katcral tenba/li'S nearly e(|ual 

 Ml leiigtii bi llie prostoininni willioiit (nnniab>]>l)ore. On the dorsal 

 surface of ea<'h oniniab)[)liore (licre is seen a small black s[)ot, the 

 (loslerior cnc. In I he po^b-i'o-la|ei'al pai'f s of I he |ii'ostomium, there 

 are visilile. Ihrengh the intcgnniciif, iri'cgnlar pigment ]>atches of a 

 bro\viii>h black colour. .Me<lian bailaclc iii'oj<'c(s a litlle bc^N'ond 



