POLYCHAETE WORMS, PART 1 213 



rocks, shells, worm tubes. Found in stomach of haddock (Georges 

 Bank, 1953, 1954, 1955, R. Wigley). They form epitokes when 

 sexually mature and may be found at the surface. This occurs from 

 May to July in Norway (St0p-Bowitz, 1941; see discussion under 

 Family) . 



Material examined. — Gulf of St. Lawrence (St. Lawrence estuary, 

 south of Anticosti Island, 8-154 fathoms), Massachusetts (Georges 

 Bank, 22-136 fathoms, R. Wigley; off Provincetown, 38 fathoms; 1 

 mile north Manomet Buoy, 17 fathoms; Massachusetts Bay, 2 miles 

 from Cape Cod Canal, 10 fathoms). 



Distribution. — Widely distributed in the Arctic. Also Iceland, 

 Faroes, Norway to Portugal, Azores, Madeira, Mediterranean, 

 Adriatic, Davis Strait to Rhode Island, Alaska to Gulf of California 

 and Mexico, Japan, South Atlantic, Antarctic. Low water to 1,889 

 fathoms; epitokous phase in surface waters. 



Glycera americana Leidy, 1855 



Figure 54,a-e 



Glycera americana Leidy, 1855, p. 147, pi. 11, figs. 49-50. — Treadwell, in Cowles, 

 1930, p. 344.— Hartman, 1944a, p. 336, pi. 16, fig. 1, pi. 18, fig. 2; 1945, p. 23; 

 1950, p. 73; 1951, p. 50.— Berkeley and Berkeley, 1948, p. 38, fig. 54.— Not 

 Andrew, 1953, p. 9 (=C tesselata Grube). — Reish, 1959, p. 82. — Knox, 

 1960b, p. 221, figs. 1-3.— Wesenberg-Lund, 1962, p. 100, figs. 44-46. 



Rhynchoholus americanus Verrill and Smith, 1874, pp. 38, 48, 70, 77, 83, 134, 137, 

 140, 169, 302, pi. 10, figs. 45, 46.— Verrill, 1881, pp. 291, 296, 301, 317, 322.— 

 Webster, 1879, p. 245; 1886, p. 145.— Andrews, 1891a, p. 289.— Sumner, 

 Osburn, and Cole, 1913, p. 623. 



Description. — Length up to 350 mm., width up to 13 mm., seg- 

 ments up to 300. Parapodia (fig. 54,a,6) w4th 4 sharply conical lips, 

 the 2 presetal ones slightly longer than the 2 postsetal ones. Branchiae 

 retractile, thin walled, emerging from a pore on the posterior face of 

 the parapodial lobe at about the level of the dorsal cirrus. When 

 fully extended, the branchiae form a conspicuous arborescent bushy tuft 

 with a short base which bifurcates several times (when not fully 

 everted, may have all stages of few to numerous, digitiform branchiae 

 showing). Proboscis with proboscideal organs of two kinds: more 

 numerous, smaller, subconical (fig. 54^/) and fewer, larger, ovate to 

 subspherical ones (fig. 54e). 



Biology. — Found at low water in sandy beaches, mud, sandy mud, 

 in oyster beds. Common in the sandy shoals where the sand is mixed 

 with some mud, gravel and shell particles, usually in areas less aerated 

 than where G. dibranchiata occurs. Dredged on muddy bottoms of 

 bays and sounds and in brackish waters. Sexually mature males have 

 been found swinuning at the surface in the evening in Massachusetts in 

 July and August (Vineyard Sound, August 26, 1875, Verrill; Eel Pond, 



