144: U.S. NATIONAL MUSEUM BULLETIN 227 



Autolytus corniitus Agassiz, 1863 



Figure 37e 



Autolytus cornutus Agassiz, 1863, p. 390, pis. 9-11. — Verrill and Smith, 1874, pp. 

 103, 296, pi. 13, figs. 65-66.— Verrill, 1881, pp. 292, 300, 304, 308, 323, pi. 

 12, figs. 4, 6.— Webster and Benedict, 1884, p. 717; 1887, p. 722.— Wilson, 

 1900, p. 351.— Mensch, 1900a, p. 270; 1900b, p. 89.— Sumner, Osburn, and 

 Cole, 1913, p. 616.— Procter, 1933, p. 139.— Hartman, 1944a, p. 338, pi. 13, 

 figs. 4-6.— Miner, 1950, p. 294, pi. 97.— Pratt, 1951, p. 329. 



Autolytus hesperidum Webster 1886, p. 110. — Tread well, in Cowles, 1930, p. 

 342.— Not Claparede, 1868. 



Myriana cirrata Treadwell, in Cowles, 1930, p. 342. — Treadwell, 1931, p. 2, fig. 2. 



Autolytus prismaticus Berkeley and Berkeley, 1948, p. 68, figs. 97-99. — Not 

 Fabricius, 1780. 



Autolytus fallax Pettibone, 1954, p. 247, fig. 29, c-f; 1956, p. 555. 



Description. — Stem form length up to 18 mm,, width up to 0.7 

 mm., segments up to 78; nuchal epaulettes lacking or short, shallow; 

 second pair dorsal cirri only slightly longer than following ; body flesh 

 colored, may be tinged with green or dusky around basal parts of 

 parapodia forming faint lateral brownish bands. 



Female stolon with 6 prenatatory, 12-18 natatory, 3-27 post- 

 natatory setigers; nuchal epaulettes inconspicuous; eggs in single 

 ventral egg sac, with eggs pale greenish. Male stolons with 6 pre- 

 natatory, 17-30 natatory, 0-10 postnatatory setigers; five pairs testes 

 in setigers 2-6 (Moore, ms.) ; body colorless or brownish. 



Biology. — Found at low water under rocks, on pihngs, in muddy 

 sand, with algae (as Laminaria), sponges, hydroids, barnacles, mus- 

 sels, as Mytilus. They construct cylindrical tubes attached to algae, 

 branches of hydroids, etc.; they may leave their tubes and return to 

 them. They are dredged up to 25 fathoms on bottoms of mud, sand, 

 with stones, rocks, shells, among tunicates (as sandy Amaroecium) . 

 Numerous specimens were obtained in the oceanographic fouling 

 studies from the New England region. Stem forms with sexual 

 buds forming are found at any time of j^ear and are especially 

 abundant in June to August (Maine, Massachusetts) ; sexual stolons 

 have been found in June, July, and August (Gulf of St. Lawrence, 

 Maine, Massachusetts), in August and September (North Carolina, 

 Wilson, 1900), in September, October, February to May in the 

 Arctic (Point Barrow, Pettibone, 1954). 



Material examined. — Gulf of St. Lawrence (Bay of Chaleurs, 

 St. Lawrence estuary), Newfoundland, Maine (Gulf of Maine; Booth- 

 bay Harbor region; the Nubble, York), New Hampshire (Rye Har- 

 bor, Hampton Harbor), Massachusetts (Marblehead; Sandwich and 

 Wellfleet on Cape Cod; Martha's Vineyard; Vineyard Sound, 25 

 fathoms), Rhode Island. 



Distribution.^ — -Arctic, Labrador to Chesapeake Bay. In low 

 water to 75 fathoms ; sexual stolons in surface waters. 



