100 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 25 



tend to become brush-like when pressed down. The posterior pygidial 

 flange is broadly flaring, or only slightly constricted. 



Specimens from southern California have been compared with type 

 specimens from eastern United States where it is known to attack the 

 commercial oyster (PI. 17). The latter are only about 2/3 as large; 

 the long palpi have a pair of fine black lines along the edges of the 

 longitudinal grooves. In other respects there is close agreement. 



Polydora websteri is widely distributed along both shores of the 

 United States, and drills in calcareous structures. 



Polydora ? quadrilobata Jacobi, 1883 



Fauvel, 1927, p. 54, fig. 18. 

 Annenkova, 1932, p. 139, figs. 6-9. 



Collections. VELERO IV Sta. 4807 (1 or more) off Point Vicente 

 light, near San Pedro, California, in 9 fms, black mud. 



The prostomium is rounded to medially incised, continued back as a 

 flattened lobe between the palpal bases to form a caruncle that extends 

 to the middle of the third setigerous segment ; eyes and a median antenna 

 are lacking. Branchiae are present from the seventh segment and con- 

 tinue back on many segments. The first parapodia are biramous, the 

 notopodium smaller than the neuropodium. The first and second neuro- 

 podial postsetal lobes are unusually prolonged and digitate; the third 

 one is less so and from the fourth the lobe is foliaceous and not digitate. 



Neuropodial hooded hooks are first present from the seventh setigerous 

 segment. The uncini have a main fang slightly more than right-angled to 

 the shaft ; the accessory tooth is small. 



The modified spines of the fifth segment number 4 or more in an 

 oblique series. Each is distally unequally bifurcated and has a bristly 

 tuft in the concavity. 



Polydora quadrilobata is known from north Atlantic and Pacific 

 oceans (see Fauvel, 1927, p. 54, and Annenkova, 1932, p. 134). 



Genus Pseudopolydora Czerniavsky, 1881 



Type P. antennata (Claparede) 1870 



Pseudopolydora sp. 



Collection. VELERO IV Sta. 2307 (1), in the San Pedro region. 



The genus may be well represented in southern California, but it is 



separable from Polydora Bosc (see above) in characters of microscopic 



