136 U.S. NATIONAL MUSEUM BULLETIN 2 27 



Description. — Length up to 4.5 mm., width up to 0.5 mm., 

 segments 22-37. Prostomium with palps short, wide, rounded 

 anteriorly; palps may project more anteriorly, extending about the 

 same length as the prostomium, with basal halves fused and distal 

 halves separated by a narrow groove or they may project more 

 ventrally, extending only about half the length of the prostomium and 

 appear to be fused except for a small anterior indentation. Dorsal 

 cirri short, slightly longer than the parapodial lobes and shorter than 

 the setae, inflated basally, tapering to narrow tips. Colorless. 



Form sexual epitokes. Male epitokes with swimming setae begin- 

 ning on setiger 8. Females with or without swimming setae, with 

 large yolky eggs and larvae attached to dorsal part of the parapodial 

 bases, 1 to 4 per segment, beginning on about setiger 8 (8-9). Eggs 

 may be compact, crowded, and also covered with mud, as is the body 

 of the female. 



Biology. — Found at low water, in sand, under rocks, on sponges, 

 on pilings among sponges, tunicates, etc. Dredged on bottoms of 

 stones, gravel, rocks, with shells, hydroids, bryozoans, tunicates 

 (as sandy Amaroecium pellucidum) . A single specimen was found in 

 the oceanographic fouling studies in the New England region. In the 

 Woods Hole region, males with swimming setae and females with eggs 

 and 3^oung attached have been found in June to September; in the 

 Chincoteague Bay region, Virginia, in May; in Ireland region, in July 

 (Southern, 1914), in Ai'ctic Alaska, in September and October 

 (Pettibone, 1954). 



Material examined. — Massachusetts (Woods Hole region, 

 Fisheries Dock, evening, June 8, 1954; Juniper Point; Hadley Harbor; 

 Martha's Vineyard; Vineyard Sound, 13 fathoms), Virginia (Chin- 

 coteague Bay near Robins Marsh). 



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

 Denmark, English Channel and the Baltic, Mediterranean, Labrador 

 to Virginia, Bering Sea, north Japan Sea, Mexico (?), Tristan da 

 Cunha (?). Low water to 75.5 fathoms; sexual forms at sm-face. 



Sphaerosyllis hystrix Claparede, 1863 



Figure 35g 



Sphaerosyllis brevifrons Webster and Benedict, 1884, p. 714 (part; from South 



Norwalk, Connecticut). 

 Sphaerosyllis hystrix Southern, 1914, p. 19. — Fauvel, 1923, p. 301, fig. 115, g-k. — 



Berkeley and Berkeley, 1948, p. 80, fig. 119.— Banse, 1959, p. 433. 



Description. — Length up to 5 mm., width up to 0.3 mm., segments 

 21 to 40. Palps fused, triangular, longer than the prostomium or 

 they may be bent down ventrally when they appear to be short. 



