118 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 25 



Flabelligera commensalis has been found most concentrated in a few 

 areas. On the Palos Verdes peninsula, near Los Angeles, it occurs among 

 the spines of the purple urchin, chiefly at a —1.0 tidal level, especially 

 in rocky bottoms. At higher tidal levels the urchins are present but lack 

 the cage-worms. Off the Palos Verdes slope, in depths of 30-50 ft, F. 

 commensalis is very abundant in association with Chaetopterus vario- 

 pedatus and many other kinds of polychaetes but no urchins. The species 

 is known only from southern California. 



Flabelligera essenbergae, new name 

 Plate 22, figs. 1, 2 ; plate 23, figs. 1-4 



Stylarioides papulosa Essenberg, 1922, pp. 379-381, figs. 1-8. 

 Flabelligera papulosa Hartman, 1959b, p. 416. 



Collections. Sta. 904-38 ( 1 ) Laguna Beach, shore, at extreme low 

 tide line; Sta. 1443-41 (2) at Arch Rock, Corona del Mar, rocky 

 shore in eel grass bed, at — 1.5 low tide line. 



The specific name is preoccupied (Hartman, 1959b, p. 416) and 

 here replaced with one in honor of the first describer. This unusually 

 modified bristle-cage worm is previously known only through an original 

 find from San Diego. The newly reported collections are also from 

 intertidal zones not far from the type locality. The apparent rarity of 

 this species in shore collections is believed to result from its inconspicuous 

 color and sluggish habit. 



Length of the body is 30 to 70 mm, width 5 to 10 mm. Color in life and 

 preserved is slatey gray. The body is widest at its anterior third and 

 tapers posteriorly to a slender end ; the forward end is truncate. The 

 body is somewhat depressed with the dorsum convex and the ventrum 

 flat (PL 23, fig. 4). Setigerous segments number 28 to 32 in smaller, 

 and to 40 segments in larger individuals. There is no investing mucus 

 sheath. 



The body is completely covered with larger papillae on the dorsum 

 (PL 22, fig. 1) and smaller ones on the ventrum (PL 22, fig. 2). Those 

 medial to the neuropodial bases are uniformly small and continued across 

 the midventrum. All are closely encrusted with sand particles which 

 cannot be removed without destroying the papillae. The lateral notopodia 

 resemble the largest papillae (PL 23, fig. 4) but are laterally prolonged, 

 tube-like epithelial investments through which the notopodial armature 

 (setae and papillae) can be extended. 



