318 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL.10 



Family Magelonidae 



The Magelonidae constitute a small, unique group, contained in a 

 single genus, Magelona Miiller. Their affinities are most notably with 

 the Spionidae on the one hand and the Chaetopteridae on the other; 

 specialization has produced a variety of structures known nowhere else. 

 The paired palpi, reminiscent of the spionids, are greatly prolonged and 

 heavily papillated. The body consists of 2 regions, an anterior one of 9 

 setigers provided with only simple, pointed setae, and a posterior one of 

 many segments provided with only simple, hooded hooks. The ninth seg- 

 ment is more or less specialized, often shorter than the others, somewhat 

 constricted, and may have setae differing from those in front. The pro- 

 stomium is a great, flat, spatulate lobe, shovellike in appearance and opera- 

 tion, with or without frontal horns at its anterolateral margins. The 

 proboscis is a large, eversible, spherical, or oval sack, smooth or somewhat 

 papillated. Parapodia are biramous throughout, notopodia and neuropodia 

 resemble each other, but the postsetal lamellae, which may be cirriform 

 to more or less foliaceous, may differ in the 2 rami. In so far as known, 

 the body tapers posteriorly and ends in a pair of elongate cirri (pi. 28, 

 fig. 11); for some species described, the posterior end remains unknown. 



The first record of any magelonid was that of F. Miiller (1858, p. 

 215) when Magelona papillicornis was recorded from Brazil. This 

 species has since been widely reported from other parts of the world, 

 including western and southern Europe, eastern America, and other 

 places, but at least some of these records might be questioned. Other 

 species have been described from widely separated places. They are as 

 follows. 



1. M. papillicornis F. Miiller (Fauvel, 1927, p. 64, with synonymy). 



2. M. longicornis Johnson (see below). 



3. M. rosea Moore (1907, pp. 201-204, pi. 16) from New England. 



4. M. obockensis Gravier (see below). 



5. M. cincta Ehlers (1912, pp. 111-112, pi. 15) from south Africa. 



6. M. pacifica Monro. 



7. M. japonica and its variety koreana Okuda (1937, pp. 247-250, figs. 

 23, 24) from Korea. 



8. 71/. pitelkae Hartman (Hancock Pacific Exped., vol. 10, no. 2). 



9. M. calif ornica, new species. 



M. longicornis Johnson (1901, pp. 414-415, pi. 11) from near 

 Seattle, Washington, remains incompletely known. It is not certain 

 whether the prostomium has frontal horns, but it was described as 



