EREANTIATE POLYCHAEÏA OF JAPAN. 227 



Botli dorsal and ventral surfaces of body are somewhat con- 

 vex, tlic foi-mer beinij; transversely marked with intersegmental 

 lines and slightly corrugated tlu'ougliout ; the latter showing 

 segment-junctions more distinctly. 



Prostomium sliglitly differentiated and disproportionately small 

 for so large a body. In front the snout bears two sul) tentacles, 

 wdiicli are conical and of a ferruginous hue from base to apex. 

 The two lateral tentacles, situated at tiie anterior border of 

 prostomium, have eacli a bluish ceratophore. Immediately behind 

 them there is a small tongue-shaped caruncle, arising nearly in 

 line with the anterior border of tlie first parapodiated segment, 

 and terminating in a groove in front of the ]30sterior border 

 of same. Tlie caruncle is deeply cordate in front, and bears at 

 the termination of tlie sinus a short, conical, ferruginous median 

 tentacle. 



Moutli opens ventrally at the anterior l)order of the 3rd para- 

 podiated segment. From the oral aperture two well-marked folds 

 run forwards t(.) the anterior prominence of snout which bears 

 the subtentacles. Tliese fields are wide in front aiul narrow 

 beliind. Two additional plaits appertain to the 2ud segment, 

 ;iiid another to tlie first. 



r)i-;iii('liia' commence to occur on the ord parapodiated seg- 

 ment. Tlicy liMvc the form of a dense arbuscle, which con- 

 sists of I) or 7 main stems springing from a. common base and 

 divides somewhiii rlieliotomiMisly into a dense bush of filaments. 

 Tlie oulei- stems have shoil er lei'iniiial proccsscs ; the inucr possess 

 Im. Ill longer hranelies am! longer terminal processes. The terminal 

 proeessi'S arc; l'erruginoiis in eolonr throughout, while the stems 

 and branches ai-e of tlie usual bluish tint. The tuft is situated 

 •close to base of dorsal bristle-papilla, and somewhat to the 



