138 



AET. II. A. IZUKA : 



Prostomium depressedl)^ conical with a rather acute apex ; 

 length IJ times the breadth at base and about thrice the length 

 of peristomium, one-third of its length dove-tailed into peristomiuni 

 on the dorsal side, with fine lateral grooves from palpi to apex. 

 No eyes visible. Palpi large. Peristomium ventrally produced 

 into 3 lobes bounding the mouth laterally and posteriorly. Body 

 round in cross- section. 



The branchiae arise from the postsetal lobe of parapodium, 

 appearing on the 5 th segment and consisting of a cirrus -like 



dorsal, and of a shorter and thicker 

 ventral, process. On succeeding seg- 

 ments, there arise short thick branchi- 

 al filaments from the dorsal side of 

 the ventral process of branchia, num- 

 bering generally 4, but sometimes 3 or. 

 5, which number persists to the 26th 

 or the 27th segment. When best 

 developed, the dorsalmost cirrus-like 

 filament of branchia is about twice the 

 length of the others and curves over 

 the back ; the next one or two are 

 separated, but the lowest 2 or 3 

 remain connected and diverge in a 

 palmate manner. The dorsalmost fila- 

 . T , . -u • ., ^ , nr. . ment suddenly disappears at about the 



A. Lanceolate bnstle from the 90th "^ ^ ^ 



segment of xinoë paimata. 30th scgmcut, whilc the othcrs gradu- 



480/1. 

 J5. Hook from the 12th segment of ally UUdcrgO rcductiou. 



n ^T'^ \i r.M, Bristles of two simple kinds: bent 



C. Hook from the 90th segment of '- 



same. 480/1. laiiccolate and hooked guarded bristles, 



[After J. P. :\roore.] 



are 



which latter 



modified in two 



