64 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 25 



3. Smaller, body less than 7 mm long; notopodial setae absent 

 Hesionella mccullochae 



4. Proboscis without terminal papillae . Amphiduros pacificus 



4. Proboscis with terminal papillae 5 



5. Body transversely barred with brown pigment (PL 5, fig. 1) ; 

 notopodial setae conspicuously dentate (PI. 5, fig. 3) ... 

 Oxydromus brunnea 



5. Body pale, not transversely barred ; notopodial setae without 

 dentations Oxydromus arenicolus glabrus 



Genus Orseis Ehlers, 1864 

 Type O. pulla Ehlers, 1864 



The body is short and has few, widely separated segments. The 

 prostomium has 3 antennae, 2 pairs of eyes and a pair of palpi directed 

 forward. The first segment has 2 pairs of tentacular cirri. The second 

 segment is the first setigerous one. Parapodia are uniramous. Dorsal 

 cirri are cirriform ; ventral cirri are present. The eversible proboscis 

 terminates in a circlet of tapering papillae. The pygidium has a terminal 

 and a pair of lateral processes. Three species are known (see Hartman, 

 1959b, p. 190) ; a fourth is here added. 



Orseis lagunae, new species 



Collection. Laguna Beach, California, intertidal ( 1 ) . 



The single individual measures 15 mm long for 10 anterior segments, 

 and width is 2.5 mm without, and 5.2 mm with, parapodia. The body 

 is short, plump and grossly resembles that of Hesione spp. The shape 

 of the prostomium and bases of antennae are very similar to those 

 shown for Orseis mathai Gravier (1907, pi. 3, fig. 22) except that the 

 antennae are more than twice as long in the specimen from Laguna 

 Beach. The prostomial eyes are large and conspicuous; the anterior pair 

 is at the widest part of the lobe, whereas the posterior pair is near 

 the postectal margins of the prostomium. The paired antennae are in- 

 serted in front of the anterior eyes, and the median one is a little in 

 front of the middistance between the anterior eyes. Palpi are very long, 

 distally inflated and directed down so as to extend back beyond the first 

 segment. 



All antennae and dorsal and ventral cirri are very long, slender and 

 cirriform, resembling one another; most of the dorsal cirri have been lost 



