212 THE ANNELIDA POLYCHAETA. 



parts relatively much reduced. (Plate 33, fig. 8; Plate 34, fig. 2, 3; Plate 35, 



fig. 1, 2). 



Two acicula occur in each parapodium excepting those of the first five 

 pairs, in which only the neuropodial is normally developed. The typical acicula 

 of the heteronereid region are shghtly curved and distally acute, with the proxi- 

 mal half colorless or nearly so and the distal half abruptly black or reddish black. 

 In parapodia of the anterior region the acicula in general are similar. In addi- 

 tion to the aciculum there is normally present in the notopodium of this region 

 a single stout seta, simple, but with a suture evident in obsolete condition, thicker 

 than the aciculum, which often protrudes freely from the surface and is strongly 

 hooked at the tip, with the distal portion dark in color, the proximal pale; the 

 cross-striated band is single. No notopodial setae other than the uncinate ones 

 are found in either of the types on any of the parapodia of the nereid division, 

 their absence being apparently normal. The neuropodials of all these parapodia 

 are well developed. They are compound heterogomphs of two types. The first 

 type, few in number and occurring on the dorsal side of the fascicle, have the 

 distal piece slenderly tapered and smooth, tip long and fine. The striated band 

 of the shafts is single except distally. In the second and more abundant type 

 the distal piece is much shorter, with the smooth tip short and distally rounded 

 and the setae extending up close to it. The natatory setae are much larger and 

 coarser than the anterior forms. The shaft is strongly cross-striate in the usual 

 double band and terminates in a homogomph socket. The distal piece is paddle- 

 Uke, clavately widening distad, at the distal end convexly rounded to a minute 

 mucron at the tip; very finely toothed along one side. All are similar in both 

 notopodial and neuropodial fascicles. (Plate 33, fig. 7; Plate 34, fig. 4-6). 



Proboscis not extruded in either type, though the maxillae extend a httle from 

 the mouth. The paragnatha are all conical, acute, and dark in color. They occur 

 in all the areas, but are much more abundant in those of the maxillary half. 



Locality. Marshall Islands: off Rongelab Island. Surface by night 

 light. 17 January, 1900. Two males. 



This species is strongly characterized by the highly modified notopodial 

 setae of the nereid division, of which but one is present in each notopodium. 

 In these the distal piece is fused with the proximal and is uncinate, the seta as 

 a whole being stouter than the aciculum, dark in color, and conspicuous. An- 

 other marked characteristic is in the form of the notocirri of the heteronereid 

 division, these having along one side a series of papillae of unusual length, above 

 which a more slender, smooth tip ordinarily projects at an angle to the main axis. 



