POLYCHAETE WORMS, PART 1 297 



Thoracic region (figs. 77,a,e; 78,a,b) with 7 setigers, with notopodia 

 beginning on setiger 2 (lacking on fii'st and sometimes on setiger 7), 

 elongate, lanceolate, ciliated up to near distal tip, supported inter- 

 nally by single long transparent aciculum, without notosetae. Inter- 

 ramal cirri dorsal to neuropodia beginning on fii'st setiger (6-7 pairs, 

 may be lacking on setiger 7), elongate, lanceolate, ciliated up to near 

 distal tip. Neuropodia lateral, with thick bundles of reddish-bronzy 

 or amber-colored neurosetae arranged in several rows. Neurosetae 

 simple, wide basall}^ and tapering to slender tips, smooth or with 

 delicate diagonal striations, the tips with fine sheaths, appearing as 

 mucronate tips, sometimes frayed (fig. 77, d-f). Setigers 5-7 with 

 setae gradually dmiinishing in number, forming a small bundle in 

 setiger 7 (fig. 78,a,b) . Neuropodial postsetal lamellae on first 3 seti- 

 gers low, with lower part slightly extended subpodally, forming a 

 subpodal papilla (sometimes referred to as ventral cirrus). On setiger 

 4, postsetal lamella may be extended subpodally to form lobulated 

 lobe with 4-6 papillae (fig. 77f, not shown by Theel or Wesenberg- 

 Lund). Setigers 5-7 with postsetal lamellae extended ventrally nearly 

 to midventral line and forming a subpodal flared flange with margins 

 finely fringed with numerous conical papillae on setigers 5 and 6 

 (fig. 78a), coarsely fringed with about 10 conical papillae (6-14) on 

 setiger 7 (fig. 786) . 



Middle or transitional region (figs. 77b, 78c) with 4 setigers (setigers 

 8-11), with notopodia more delicate and cylindrical (sometimes 

 lacl-dng on setigers 8-10), without interramal cirri. Neuropodia 

 elongate conical with few long delicate setae, with subpodal flared 

 flange with margins finely papillate (similar to setigers 5 and 6). 



Posterior region beginning on setiger 12 (figs. 776, 78d). Cylindrical 

 notopodia with more slender tips, ciliated up to near tips, supported 

 by internal acicula. Neuropodia long, c^dindrical, supported by 

 few acicula with tips curved, with small bundle of long slender setae. 

 Setae wider basally, tapered to fine mucronate tips (setae may be 

 broken and worn in various irregular ways, including some with 

 split tip as shown by Theel). Subpodally \vith variable number of 

 conical papillae (0-4). With transverse dorsal ciliated bands between 

 notopodia. Pygidium with 2 filiform anal cirri (2 lateroventral ones 

 according to Webster and Benedict; 2 dorsal and 1 ventral one 

 according to Eliason). Color: white or yellowish white; setae 

 yellowish brown or reddish amber colored. 



Biology. — They probably live in tubes. They are delicate, 

 fragile, fragmenting readily. Dredged on bottoms of fine to coarse 

 sand, soft mud, clay with shells, sand with gravel and shells. They 

 may be very abundant, as Eliason (1920) reported 349 specimens in 

 0.4 square meter in the Oersund region. 



