126 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 15 



width with parapodia is to 5.2 mm at the widest part or segment 16. 



The prostomium is approximately rectangular and has a straight 

 anterior margin; its posterior half is pigmented. There are no visible 

 eyespots. Nuchal organs are inconspicuous between the upper edge of the 

 first notopodia and the postectal margin of the prostomium. Frontal an- 

 tennae taper distally; they resemble the first pair of ventral cirri except 

 that they are not constricted near the base. Posterior antennae originate 

 just behind and ventral to the anterior pair; they are broader and slight- 

 ly longer than the first pair. When the proboscis is retracted the lateral 

 margins of the mouth extend through the first and most of the second 

 segment. The lower lip with its outer margins extends from the middle 

 of the second, to the middle of the fifth segment. 



The proboscis has 14 rows of bifid terminal papillae and the same 

 number in the subterminal rows. These number 10 to 13 in each row 

 and they decrease in size going proximally ; there is no distinct middorsal 

 or midventral papilla. The proximal surface of the proboscis is smooth 



(ng. 1). 



Parapodia are biramous throughout. The first are large, directed for- 

 ward and project beyond the prostomium. The first neuropodium exceeds 

 its notopodium in size; the ventral cirrus resembles the frontal antennae. 

 The first neuroacicular lobe is acutely prolonged and nearly as long as 

 the ventral cirrus. Neurosetae number about 15 to 20 in a fascicle. The 

 first notopodium has a small notopodial cirrus and its setae include both 

 barred preacicular and lanceolate postacicular ones. 



Farther back the parapodial rami are widely separated from each 

 other (fig. 2). Interramal cirri are involute and may be first present 

 from segment 9 where they are tiny, or not until segment 11. They 

 increase in size gradually and come to be spiralled (fig. 3) by segment 

 17. Typical notopodia have a small postsetal foliaceous lamella that is 

 superior in position. Notopodial cirri are short, conical and smaller than 

 their respective interramal cirri except in anterior segments where the 

 latter are lacking. 



Acicular lobes in both notopodia and neuropodia are conical. Acicula 

 occur singly; they project from the distal end of the lobe and are re- 

 curved at the tip (fig. 4). An erect lobe at the upper edge of neuropodial 

 lobes is present as a small papilla from about segment 16; it appears as 

 a separation between the presetal and postsetal lobes. This papilla en- 

 larges gradually so that by segment 27 it is as shown in fig. 3 ; it is never 

 as large or long as the comparable process in A. dicirris (see above). 

 Farther back it comes to be only slightly longer; in posterior segments 

 it decreases and is probably absent from a considerable posterior portion. 



