POLYCHAETE WORMS — PETTIBONE 577 



Genus Branchiomma KoUiker, 1858 



Tori of thorax with a single row of avicular uncini, without hoclike 

 setae. Branchial filaments with paired dorsal appendages (st3^1odes) 

 on outer sides of branchial filaments. 



Branchiomma infarcta (Kroycr, 1856) 



Sabella infarcta Kroyer, 1856, p. 21. 



Dasychone infarcta Malmgren, 1865, p. 403, pi. 28, fig. 86. — Augener, 1928, 

 p. 803, pi. 11, fig. 11.— Gustafson, 1936, p. 10.— Berkeley and Berkeley, 

 1943, p. 130; 1944, p. 5.— Gorbunov, 1946, p. 39.— Zatsepin, 1948, p. 160, 

 pi. 39, fig. 1.— Wesenberg-Lund, 1950a, p. 57; 1950b, p. 130; 1951, p. 121; 

 1953, p. 107. 



Branchiomma infarcta Johansson, 1927, p. 157. 



Description: Collarette 4-lobed — 2 ventral, 2 laterodorsal. Bran- 

 chial filaments without eyespots, banded with pink. Tube mem- 

 branous, free end covered with mud. 



New records: Labrador: Kaipokok Inlet, Backway, east end, 

 middle, and west end Lake Melville, Goose Bay, 9-80 fms., on bot- 

 toms of silt, mud, and sand with mud and rock; 43 specimens, Sta- 

 tions, 7, 28, 32, 35, 39, 40, 47, 59, 60, 63, 67, 79. 



Distribution: Widely distributed in the Arctic: Siberian and 

 Canadian Arctic, Davis Strait, Greenland, Spitsbergen, Novaya 

 Zemlya, Kara Sea. Also Iceland, Norway, Denmark Strait; Hudson 

 Bay to Labrador; Bering Sea. In low water to 411 fathoms. 



Genus Chone Kroyer, 1856 



Chone duniri Malmgren, 1867 



Chone dunSri Wesenberg-Lund, 1953, p. 109.— Pettibone, 1954, p. 339, fig. 39,k,l. 



New record: Labrador: Strait of Belle Isle, 8 fms., soft mud; 

 2 specimens. Station 17. 



Distribution: Widely distributed in the Arctic. Also Iceland, 

 Norway to North Sea, Madeira, Mediterranean, Adriatic; Lab- 

 rador; Florida; Peru. In 8 to 889 fathoms. 



Genus Euchone Malmgren, 1865 



Large ventral groovelike depression with flared sides on posterior 

 segments. Collarette 2-lobed, with small midventral slit. 



Key to the species of Euchone from Labrador 



1. Collarette obliquely slanted, longer ventrally. Branchial filaments end in 

 long slender tips. Abdominal region with 2 pairs small ventral shields 



per segment E. papillosa 



Collarette nearly straight. Branchial filaments end in short lirabate tips. 

 Abdominal region with one pair large ventral shields per segment . E. analls 



