474 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 83 



Parapodia anteriorly with dorsal and ventral lobes about equal 

 (tig. 49, b) and subcylindrical, with dorsal and ventral cirri exceed- 

 ing lobes in length; median parapodia with relatively larger and 

 more conical dorsal lobes and longer, slenderer ventral lobe, with 

 dorsal cirri relatively longer, distally extending beyond tips of 

 setae; posterior parapodia similar to median parapodia except for 

 further elongation of dorsal lobes and cirri (fig. 49, c). 



Setae (fig. 49, d-f) all composite; pale amber, appendage deeper 

 amber than shaft; falcigerous homogomph notosetae (fig. 49, /) first 

 present in twentieth setiger, accompanied by homogomph pointed 

 setae; at twenty-second setiger three or four homogomph notosetae 

 replace all other dorsal setae, this order continuing to posterior end. 



Anal cirri two, exceeding in length the longest dorsal cirri by 

 about one-half. 



Holoti/pe.—U.S.'NM. no. 20203. 



Distrihution. — Pacific Grove, Calif, (type), collected by Dr. R. M. 

 Eakin; Fort Bragg and vicinity, Calif.; a much larger specimen, 

 agreeing well with the California specimens, from Port Orchard, 

 Wash. Dr. Eakin reported that his specimens were taken from the 

 ambulacral groove of the starfish Patiria miniata. 



Remarks. — The unusually large number of paragnaths on the oral 

 ring and their disposition readily set this species apart from any 

 other known species of this genus. In its parapodial and setal 

 structures it is nearest to N. neordgripes., new species, and N. natans, 

 new species. 



NEREIS (NEREIS) NATANS, new species 



Figure 50 



Measurements. — Length, 8 mm including anal cirri; width, 0.65 

 mm at peristomium, 0,8 mm without, 1.9 mm with parapodia at 

 geventh segment; number of segments, 51, including 13 anterior pre- 

 natatory, 25 natatory, 11 postnatatory, and 1 anal. 



Description. — Prostomium (fig. 50, a) about as wide as long, nar- 

 rowest at anterior end where antemiae are attached; provided with 

 four very large dark-brown bulging eyes (fig. 50, a), the two of 

 each side almost touching. 



Antennae (fig. 50, a) slightly longer than anterior base of prosto- 

 mium at point of attachment ; separated at bases ; extending distally 

 beyond the palpi. 



Palpi cylindrical, with medioventral surfaces compressed, their 

 ectal margins almost parallel (fig. 50, a) ; palpodes extending ante- 

 riorly only slightly beyond prostomium; palpogtyles spherical, 

 curved ventrad. 



Peristomium about li/^ times as long as segment 2 (fig. 50, a) and 

 as wide; smooth dorsally, ventrally forming a lower lip, which i^ 



