COMPLETE HARTMAN: POLYCHAETES FRuM CALIFORNIA 99 



The lower, small fascicle of setae contains only small, distally pointed 

 ones of a single kind. 



Hooded neuropodial hooks are first present from the seventh, or 

 second postmodified segment. Seen individually, they have a bifid tip 

 with the main fang slightly acute to the shaft and the distal tooth 

 unusually slender though moderately long. 



Color pattern is characteristic in some individuals, or it may be faded. 

 The large palpi are crossed by 4 or 5 bars of black pigment. A similar 

 melanistic pigment surrounds the anterior and lateral margins of the 

 prostomium, and forms paired black spots on the dorsal side of segments 

 2 to 4. 



In southern California Polydora limicola is one of the chief fouling 

 species, depositing muddy debris on denuded surfaces. It is associated 

 with other polychaetes, including the following: Dorvillea articulata 

 (Hartman), Halosydna johnsoni (Darboux), Nereis mediator Chamber- 

 lin, Ophiodromus pugettensis (Johnson), Polydora ligni Webster and 

 Hydroides norvegica Gunnerus. 



Polydora limicola was originally described from the Commander 

 Islands in the Arctic region ; it was then found very abundant in the 

 upper horizon of the sublittoral zone, covering stones with an unbroken 

 sheath, chiefly in sandy and muddy bottoms. In southern California, it 

 occupies much the same habitat, in intertidal areas, along breakwaters, 

 and on the bottoms of ships. 



Polydora websteri Hartman, 1943 

 Plates 16, 17 



Collections. Newport Bay, California, in intertidal flats, in shells 

 of oysters; Coos Bay, Oregon, in shells of pectens. 



Calcareous structures, especially shells of bivalve mollusks, occurring 

 in littoral zones of temperate or warm water seas, are frequently 

 drilled by this spionid. In Newport Bay it is especially abundant in 

 oyster beds, especially of Ostrea lurida Carpenter, where it causes U- 

 shaped etchings on the outer surface of the exposed valve (PL 16). In 

 Coos Bay it attacks pecten shells (PI. 17) in the same manner. 



This species is best distinguished from nearly related ones by the 

 character of the large spines of the fifth segment. Seen individually, 

 they are falcate, and have a broadly attached flange (not a tooth) on one 

 side, in the region of greatest concavity. These spines number 7 to 9 in 

 a series, and are accompanied by slenderer, distally pointed setae that 



