4b. Eyes present; nuchal organs large (Figure 30-68a); body broad, up 

 to 1 mm wide including parapodia 5 



5a. Composite falcigers with subterminal guards (Figure 30-68b,b'); 



dorsal tooth set back from anterior margin *of pharynx (Figure 30- 



68a) Pionosyllis sp. C, p. 30-75 



5b. Composite falcigers without subterminal guards (Figure 30-70b,c); 



dorsal tooth near anterior margin of pharynx 



Pionosyllis sp. D, p. 30-75 



Pionosyllis weismanni Langerhans, 1879 

 Figures 30-59, 60a-e 



Pionosyllis weismanni — Ben-Eliahu, 1977:50, fig. 20a-g. 



MATERIAL EXAMINED: 

 Gulf of Mexico BLM-OCS: 



SOFLA 18C-11/80 (5 spec, USNM 89892); MAFLA 2211E-7/76 (1 spec), 

 2211K-8/77 (1 spec, USNM 65681), 2423J-7/76 (1 spec), 2645B-7/76 (1 

 spec), 2645H-7/76 (2 spec), 2645F-2/78 (2 spec, USNM 65682), 2645H- 

 2/78 (1 spec); STOCS HR1-4 7/76 (1 spec), HR1-2 F/76 (3 spec, USNM 

 89893), HR1-6 F/76 (1 spec, USNM 89894). 

 DESCRIPTION: 



Length, to 4.2 mm (previously reported to 17.7 mm); width, to 0.25 mm. 

 Body small, slender; complete specimens with up to 83 setigers. Prosto- 

 mium oval to rectangular, longer than broad, fused with peristomium 

 middorsally (Figure 30-60a). Eyes variable, usually numbering four, 

 small, in trapezoidal arrangement, with up to two ocular spots at base 

 of palps. Antennae and tentacular cirri long, smooth to weakly arti- 

 cled. Palps elongate, separate. Nuchal organs as small lobes at post- 

 ectal corners of prostomium. First pair of dorsal cirri either long and 

 slender, or similar in length to those following; remaining dorsal cirri 

 short, with slightly inflated, glandular tips. Ventral cirri digiti- 

 form, usually shorter than parapodia. Anal cirri paired, long, slender. 

 Superior simple seta straight, distally truncate (Figure 30-60b), pres- 

 ent from midbody region. Composite falcigers with homogomph shaft- 

 heads, and smooth or lightly serrate, bidentate blades (Figure 30- 

 60c, d). Inferior simple seta stout, strongly bidentate, with several 

 subapical guards (Figure 30-60e); generally present from midbody region. 

 Pharynx extending to setigers 4-5, with subterminal tooth. Proventricle 

 extending from setigers 4-6 to 6-8, with about 21-35 indistinct muscle 

 cell rows. 



REMARKS: These specimens exhibit several of the "variant" characters 

 ascribed by Ben-Eliahu (1977:50) to individuals of Pionosyllis weisman- 

 ni : 1) antennae, tentacular and first pair of dorsal cirri smooth rather 

 than articled; 2) first pair of dorsal cirri long or short; 3) setal 

 shaft-heads homogomph rather than heterogoraph; and 4) inferior simple 

 seta acicular rather than capillary. P_. weismanni is newly reported 

 from the Gulf of Mexico. 



PREVIOUSLY REPORTED HABITAT: Intertidal to 200 m; among vermetids and 

 coralligenous substrates. 



GULF OF MEXICO BLM-OCS OCCURRENCE: Widespread off Florida and one 

 station off central Texas (Figure 30-59); 19-106 m; coarse sand, silty 

 fine sand. 



30-67 



