186 AET. II. A. IZUKA I 



cirri. P^pi are slightly depressed dorso-ventrally and are bent 

 downwards and outwards at tip. 



Peristomium very short, being less than J the length of the 

 succeeding segment ; peristomial cirri two on each side ; ventral 

 cirrus about | as long as dorsal cirrus. Segments I.^ — III. curved 

 so as to keep parallel to the outline of mouth. 



Parapodium moderately elongate, its infero -lateral margin 

 sloping downwards and inwards from the extreme apex ; aciculse 

 about 4 ; bristles stout, falcate, the end-piece with 3 teeth. 

 Dorsal cirrus annulated, borne on a prominent cirriphore ; ventral 

 cirrus small, not annulated, arising from base of parapodium 

 and not reaching to tip of same. Proboscis short, thin- walled ; 

 œsophagiis moderately long, extending through segments VII — 

 XXII, with the usual chitinous lining, which anteriorly terminates 

 in a "trephine" of 10 crenulations. Proventriculus extends 

 thi'ough segments XXIII — XLY. 



The posterior extremity of the worm is capable of producing 

 successive crops of collateral sexual buds. Each bud shows an 

 external structure similar to that of the mother individual and is 

 provided with a pair of long and annulated anal cirri. 



The tail buds, 14 in number, present various stages of de- 

 velopment. They are attached in a cluster to the ventral aspect 

 of the posterior end. Among them, only three have reached an 

 advanced stage of development, though the eyes are observable in 

 a number of seven at least. Seen from the ventral side, the cluster 

 shows an interesting feature, in that at its base and in the median 

 une it includes three buds which as yet show no segmentation but 

 are each provided with two distal processes, the " Anlagen " of 

 anal cirri. 



One of the better developed bud is elliptical in shape, con- 



