54 U.S. NATIONAL MUSEUM BULLETIN 2 27 



Distribution. — Off Massachusetts to north of Puerto Rico, Ice- 

 land, Great Britain, Ireland, Azores, off Southern California. In 100 

 to 1,443 fathoms. 



Family Chrysopetalidae 



Body short or elongated, segments few or numerous. Prostomium 

 distinct, with usually 3 antennae, 2 ventral palps, 4 eyes (0, 2, or 4). 

 Tentacular segments more or less fused with prostomium, with 1 to 

 4 pairs tentacular cirri. Parapodia biramous; notosetae in lateral 

 tufts, curving dorsally and forming fan-shaped groups or transverse 

 rows; notosetae simple, usually expanded to form paddlelike setae 

 or paleae (exception: Dysponetus). Neurosetae compound. With 

 dorsal and ventral cirri. Proboscis strongly muscular, usually 

 provided with a pair of chitinous stylets. 



Contains only one New England genus. 



Genus Dysponetus Levinsen, 1879 



Taphus Webster and Benedict, 1887; type (monotypy): Taphus hebes Webster and 

 Benedict, 1887; *= Dysponetus pygmaeus Levinsen, 1879. 



Type (monotypy): Dysponetus pygmaeus Levinsen, 1879. Con- 

 tains only one species. 



Dysponetus pygmaeus Levinsen, 1879 



Figure 12 



Dysponetus pygmaeus Levinsen, 1879, p. 9, pi. 1, figs. 1-6. — Annenkova, 1935, 

 p. 233; 1938, p. 138.— Wesenberg-Lund, 1950b, p. 64; 1953, p. 47.— 

 Uschakov, 1955, p. 168, fig. 45. 



Taphus hebes Webster and Benedict, 1887, p. 716, pi. 8, figs. 113-118. 



Description. — Length up to 3 mm., width up to 1.5 mm., segments 

 11-15. Body minute, elongate ovate, widest in the middle, convex 

 dorsally and ventrally. Prostomium may be sunk between the first 

 pair of parapodia, oval, with 3 short elliptical antennae on anterior 

 margin, a pair of short globular ventral palps, without eyes or a minute 

 pair visible when living. Tentacular segment indistinct, with a pair 

 of tentacular cirri just posterior to prostomium, similar to antennae. 

 First 2 setigers with dorsal cirri and notosetae only. Parapodia 

 distinctly biramous from setiger 3 on. Notopodia indistinct, with 

 a radiating bundle of numerous notosetae emerging dorsolaterally 

 from body, curving dorsally and posteriorly. Notosetae dark brown- 

 ish, simple, curved, transversely striated, with few stout scattered 

 spines along convex margin (notosetae do not form expanded paleae 

 as in other chrysopetalids). Dorsal cirri with bulbous cirrophores 

 below the notosetae; styles rather thick, digitiform, extending about 

 the length of the notosetae. 



