BENTHIC POLYCHAETOUS ANNELIDS — REISH 143 



Abdominal postsetal lobes of notopodium and neuropodium folio- 

 ceous (fig. 2d). Dorsal cirrus lacking. Setae all hooded hooks con- 

 sisting of two teeth at nearly right angles (fig. 2e), numbering about 

 12 per each lobe of parapodium. 



Remarks : Twenty-one species have been described previously for the 

 genus Magelona. Jones (1963) recently listed the known species and 

 included a key to these species. Magelona alata belongs to that 

 group of nine species possessing bidentate hooded hooks in the pos- 

 terior region. This group can be divided further by the presence or 

 absence of frontal horns. Magelona alata has frontal horns as do M. 

 annulata Hartman-Schroder (1962), AI. x>hyllisae Jones (1963), M. 

 longicornis Johnson (1901), AI. pacifica Monro (1933), and AI. cerae 

 Hartman and Reish (1950). Alagelona alata, AI. pacifica, and AI. 

 phyllisae all have single-winged capillary setae through segment 9. 

 These three species can be distinguished by the different degree of 

 development of the parapodial lobes. 



Ecology: Magelona alata was taken in depths of 11-67.1 meters, 

 more frequently from silts than from fine and very fine sands. 



Type locality: Station 5 (fig. 1), Bristol Bay area of Bering Sea, 

 56°54' north latitude and 163°45' west longitude at a depth of 67.1 

 meters. 



Type material: Holotype, three paratypes, and additional specimens 

 have been deposited in the U.S. National Musemn, 



Family Spionidae 



Prionospio malmgreni Claparede 



Prionospio malmgreni Claparede, 1870, p. 73. — Hartman, 1948, p. 36; 1961, 

 p. 29. — Pettibone, 1954, pp. 282-284, figs. 32i-k. 



Material: Stations 21(1), 43(1), G-l(l), G-5(l), B(5), R-4(l); 

 Bering, Chukchi, and Beaufort Seas; fine sand or silt. 



Spio filicornis (Miiller) 



Nereis filicornis Miiller, 1776, p. 218. 



Spio filicornis.— Hartman, 1941, p. 293.— Pettibone, 1954, pp. 284-285, figs. f-h. 



Material: Stations 5(1); Bering Sea; silt. 



Spiophanes bombyx (Claparede) 



Spio bombyx. Claparede, 1870, p. 485. 



Spiophanes bombyx. — Berkeley and Berkeley, 1952, pp. 22-24, figs. 42-43. — 

 Hartman, 1961, p. 50. 



Material: Stations 15(1), 34(2), 53(1); Beaufort Sea; fine or very 

 fine sand. 



Distribution: Known previously from the Mediterranean Sea, 

 Vancouver Island south to CaUfornia and Japan. These four speci- 



