EREANTIATE POLYCHAETA OF JAPAN. 79 



peculiarly attenuated. To the naked eye the dorsal covering 

 appears to be composed of mucilaginous substance and sand ; but 

 mici'oscopically this layer is made up of a vast series of fine 

 hairs with hooked tips (hg. 11) similar to those of Aphrodita, 

 thougli the liair as a wliole is much more slender. 



Ventral smface of body covered with numerous minute, 

 globular papillae. 



Prostomium prominent and rounded, with a little conical 

 papilla anteriorly in place of a median tentacle. Ocular peduncles 

 are rather small, with no trace of pigment. On the median 

 anterior jiortion of prostomium, tliere observed a smooth tongue- 

 shaped process, which from its concavity superiorly is spoondike ; 

 posteriorly is a very deep pit on each side of the nuchal ridge 

 of prostomium. Moreover, after removal of the first elytra a 

 somewhat triangular tliin lamella, with a point in front, projects 

 forward beyond the ocular peduncles and partly shades the side 

 of prostomium. 



N'entrai cirrus subulate and short ; posteriorly, however, it 

 becomes elongated. 



Great dorsal spines, forming a conspicuous fringe to tlie 

 sides of tlie body, have a lustrous brown colour, and their tips 

 arc si]ni)!(' ihi'ougliout ((ig. 12). Ventral bristles (fig. 13) lean 

 towai'ds the siriiftiirc schmi in Aplii'odlta, and it is easy to con- 

 ceive ilic passage^ fi-om the densely spinous ventral tips of such 

 as LdclmdloDifc jitptiu'tA'd to tlie liaiiy condition of this species, 



Aiitd'iormnst S or U ])airs of i)arapodia diflbr from the suc- 

 ceeding ill having a sei-ies of minntely sei-rated bristles, along 

 witli one or more stout sliarj)-headed bi'ownish spines. 



Tlie alisence of tlie long median prostomial and the lateral 

 tentacles is diagnostie : tlio long subtentacles, however, present, 



