116 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 25 



of long lobes. The mouth is a large, broad slit below and behind the 

 prostomium. A pair of thick, longitudinally grooved palpi is inserted 

 ventrolateral to the mouth. The palpi are extremely extensile and may 

 be prolonged to five times the contracted length. The alimentary tract 

 consists of a slender esophageal tube, followed by a large secretory sac, 

 and this by the voluminous, brick-red stomach. At its posterior end the 

 stomach is abruptly narrowed to the alimentary tract, which is looped 

 and continues posteriorly to a terminal anus. A single pair of large, 

 yellow, U-shaped nephridia occupies much of the coelomic space in the 

 thoracic region ; each opens externally in a small papilla located one on 

 either side of the first segment. Tubes are not known to be constructed. 

 The family is known for only nine genera of which five are to be 

 found in California. The other four genera are limited either to single 

 records from widely spaced geographic areas, or to restricted seas (see 

 Hartman, 1959b, pp. 413-423). These five genera are recognized for 

 14 species, distributed in shallow intertidal seas to deep, basin depths 

 off southern California. Another nearly related pelagic form is Poeobius 

 meseres Heath, which is more fully discussed elsewhere (Hartman, 

 1955b, p. 52). 



Genus Flabelligera Sars, 1829 

 Type F. affinis Sars, 1829 



By definition the body is encased in mucus which is translucent, 

 glass-clear, and does not become covered with sand or mud. The 

 epithelial papillae are completely covered by the sheath and the setae 

 are covered except for their distal ends. Notopodial and neuropodial 

 setae of the first segment are longest and directed forward to form a 

 cephalic cage. Farther back the notopodial setae are similar to those 

 of the first segment. Neuropodial setae from the second segment are 

 falcigerous, composite, and usually number one or few in a parapodium. 

 The prostomium is a small lobe surmounted by many oral tentacles. 



Only one of the 3 species named below fully agrees with this diagnosis. 

 Flabelligera infundibularis (Johnson) is encased in a thick, clear mucus 

 sheath. F. commensalis and F. essenbergae differ in that they are not 

 encased in a mucus sheath, and the neuropodial falcigerous setae are 

 not clearly composite. They are retained in Flabelligera because they 

 agree in other respects. 



