Ilo 



K. IZÜKA. 



The first or the cephalo-buccal segment is obliquely truncated in 

 front at au angle of about 60" to the body axis (figs. 1 and 2). The 

 truncated end, which faces dorsally and forms the cephalic plate, exhibits 

 a median elevation laterally bounded by two slightly depressed furrows. 

 This elevation is anteriorly continuous with a small protuberance at the 

 ventio-median point of the cephalic plate edge. The dorsal and the 

 lateral edges of the cephalic plate form a thin rim. This may be said as 

 b3Ìng serrated in the dorsal part, the serration becoming more pronounced 

 as we follow it laterally on either side of the dors vmedian line. The 

 lateral portions of the rim had better hi said as being furnished with 

 fringing cirri of unequal lengths, rather than to describe them as very 

 deeply indented (fig. 2). The mouth opens on the ventral side of the 

 head end. In the larger specimen the proboscis is seen slightly protrud- 

 ed (fig. 3). 



The second to fourth segments are of about the same length. The 

 fifth and all the succeeding segments are slightly longer, though nearly 

 equally long amongst themselves. 



The last or the anal segment (fig. 4) has the vrivtro-posterior margin 

 thinned out into a rim which shows four angular longitudinal edges. 

 The dorso-posterior margin is expanded into a petaloid plume having six 

 corners, eaoh of which is prolonged into a slender cirrus. The anus lies 

 dorsal to the petaloid plume, in the dorso-median line of the segment in 

 question. 



The ce.phalo -buccal and the anal segment are entirely destitute of 

 bristles. The remaining nineteen segments are all s-tigerous. 



The second segment possesses on either side a flattened group of 

 short acicular seta?, of which two kinds, the slender and the stout (fig. 8, 

 a aiid b) are distinguishable. Neither uncini nor capillary setae occur 

 in this segment. 



The third to twentieth segments have each, on either side, two 

 flattened groups of bristles representing the dorsal and the ventral ramus 

 of the. totally or nearly totally suppressed parapodium. The dorsal group 

 consists of capillary setne. These are present in two forms. Both are 



