200 PROCEEDINGS OF THE NATIONAL MUSEUM vol. us 



subbiramous. Notopodia small, with notoacicula only. Neuropodia 

 elongated, with presetal and postsetal lips. Neurosetae of 2 kinds: 



1) long, slender, with coarse serrations basally, with capillary tips; 



2) shorter, with few serrations and slightly hooked tips. Elytral 

 pairs 14-18 (often missing); elytrophores on segments 2, 4, 5, 7, 9, 11, 

 13, 15, 17, 19, 21, 23, 26, 29 (14 pairs, as in holotype P. ploa), 32, 35 

 (16 pairs, as in holotype A. longicirrata) , 38?, 41? (18 pairs, as in P. 

 atlanticus; exact arrangement not stated). Dorsal cirri on non- 

 elytra-bearing segments long, tapered. Ventral cirri short, tapered. 

 Pair of long anal cirri. Pharynx of usual polynoid type, with jaws 

 and circlet of 18 papillae. With clavate glandular processes at bases 

 of ventral cirri and at ventral bases of parapodia; with row of glandular 

 prominences on ventroposterior borders of neuropodia and large 

 glandular structures in upper part of neuropodia. 



Podarmus ploa Chamberlin 



Figures 24-26 



Podarmus ploa Chamberlin, 1919, p. 46, pi. 6, fig. 6, pi. 7, figs. 1, 2. 



Podarmus atlanticus Monro, 1930, p. 42, fig. 7.— St0p-Bowitz, 1948, p. 13, fig. 9. 



Ancistrosyllis longicirrata Berkeley and Berkeley, 1961, p. 658, figs. 5-7. 



Material examined: Holotype of Podarmus ploa from off Easter 

 Island, South Pacific, from plankton (USNM 19458). Holotype of 

 Ancistrosyllis longicirrata Berkeley and Berkeley from off Peru, South 

 Pacific, from plankton (loan from Cyril Berkeley, now deposited in 

 USNM 30990). 



Description: Length to 13 mm., width including setae to 4 mm., 

 segments to 45. Body widest toward anterior region, tapered ante- 

 riorly and posteriorly, convex dorsally, flattened ventrally, with 

 parapodia very long, length exceeding width of body. Transparent. 

 Prostomium bilobed, rounded anteriorly, without cephalic peaks. 

 Median antenna with ceratophore in anterior notch, with style long, 

 slender, tapering, smooth; lateral antennae with ceratophores at 

 nearly same level as median antenna but inserted slightly ventrally, 

 with styles similar to but shorter than median antenna; with pair of 

 thick, contractile, tapering palps (thus variable in length), with pair 

 of glandular clavate processes below palps; with 2 pairs of light- 

 colored eyes, anterior pair lateral in position, posterior pair postero- 

 dorsal. Tentacular segment achaetous, lateral to prostomium, with 

 2 pairs of tentacular cirri on distinct ceratophores, lower pair similar 

 to medium antenna, upper pair longer. First setigerous segment 

 (segment 2 or buccal segment) with first pair of elytrophores and mid- 

 dorsal semicircular flap extending on posterior part of prostomium; 

 ventrally it forms posterior lip of mouth, with extra long ventral cirri 



