88 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 22 



Family HESIONIDAE 



A small white hesionid, represented by fragments only, has been 

 taken only in subsill parts of San Pedro and Santa Catalina Basins. 

 It may represent an unknown genus and species. 



Family PILARGIDAE 



Genus ANCISTROSYLLIS Mcintosh, 1879 



Ancistrosyllis Ptentaculata Treadwell, 1941 

 Treadwell, 1941, p. 1, figs. 1-3. 

 Hartman, 1947, p. 498. 



Numerous individuals come from Santa Monica, San Pedro, Santa 

 Cruz, Tanner and Velero Basins. They are not as large or as well 

 developed as those from shallower areas, but agree in other respects. 

 Characteristic features include the presence of thick, curved notopodial 

 spines from the fourth or fifth segment, continuing posteriorly through- 

 out the rest of the body. Antennae and dorsal cirri are long and filiform. 

 The posterior margin of the prostomium is usually straight or may be 

 incised medially, as originally shown. Specimens from Santa Cruz Basin 

 have deep yellow bars across anterior segments and similar pigment 

 spots on upper bases of parapodia ; these fade in alcohol. 



A specimen from Velero Basin differs in that the surface epithelium 

 is papillated. 



A. tentaculata was first described from Long Island, New York, 

 and reported from shallow sea bottoms off southern California (Hart- 

 man, 1947, p. 498). It is typically a shallow water species. 



Genus PILARGIS Saint- Joseph, 1899 



Pilargis hamatus, new species 

 (Plate 7, figs. 4-6) 



The specimen selected as type comes from Santa Catalina Basin 

 (Sta. 3025) ; others are from San Pedro and Tanner Basins. The type, 

 in 4 pieces, measures 27 mm long and 2 mm wide. Others, somewhat 

 larger, measure to 30 mm long. The body is prolonged and greatly 

 depressed. Posterior segments are dark reddish-brown and irregularly 

 strewn with dark specks that fade out in alcohol. The frontal margin 

 of the prostomium is deeply incised medially; it terminates in a pair of 



