Lb. Spiked notosetae with blunt tips (Figure 28-32c) 



Amphiduros sp. B, p. 28-34 



Amphiduros sp. A 



Figures 28-29, 30a-g 



MATERIAL EXAMINED: 

 Gulf of Mexico BLM-OCS: 



SOFLA 16D-11/80 (1 spec, USNM 75315), 16C-4/81 (1 spec, USNM 75314); 

 MAFLA 2211E-7/76 (1 spec); STOCS 6/II-5 W/76 (1 spec, USNM 75212). 

 DESCRIPTION: 



Length, 2.0+ mm; width, to 1.3 mm. Body relatively stout; all specimens 

 incomplete with up to eight setigers. Prostomium rectangular, with two 

 pairs of large, lentigerous eyes, anterior pair larger and farther apart 

 (Figure 28-30a). Antennae slender, cirriforra, median antenna about half 

 length of lateral antennae. Palps with fairly long bases and styles, 

 similar in length to lateral antennae. Nuchal organs as long, curved 

 ridges along postectal margins of prostomium. Most tentacular cirri 

 missing, few remaining ones cirriform, smooth to indistinctly articled 

 with long joints. Parapodia biramous from setiger 2, with small noto- 

 podia below dorsal cirrophores, neuropodia stout with digitiform to 

 triangular presetal lobes (Figure 28-30b). Dorsal cirri short, smooth, 

 cirriform; ventral cirri fairly long, slender. Notosetae including 

 single, stout acicular spines (Figure 28-30c); slender setae with long 

 serrations and truncate tips (Figure 28-30d); cross-striated spiked 

 setae (Figure 28-30e) tapering to long, fine tips; and extremely fine, 

 smooth capillary setae (Figure 28-30f). Neuropodial falcigers with long 

 extension of shaft-head entire; blades long, curved, faintly serrate, 

 with minutely hooked tip and subapical spine (Figure 28-30g), blade- 

 length ratio 3.8-6.1:1. Pharynx extending to setigers 2-5, margin 

 surrounded by 30-40 slender fimbriae. One specimen with eggs present in 

 parapodia* 



REMARKS: Amphiduros sp. A is similar to A. pacificus Hartman, 1961, 

 from California. It differs from the latter in lacking notopodia on 

 setiger 1, and in having spinous and smooth, slender notosetae rather 

 than furcate notosetae. 



GULF OF MEXICO BLM-OCS OCCURRENCE: Three widespread records off Texas 

 and western Florida (Figure 28-29); intermediate depths, 43-98 m; coarse 

 to fine sand, silty clay. 



Amphiduros sp. B 



Figures 28-31, 32a-f 



MATERIAL EXAMINED: 

 Gulf of Mexico BLM-OCS: 



MAFLA 2315A-2/73 (1 spec), 25281-9/77 (1 spec). 

 DESCRIPTION: 



Length, 1.8+ mm; width, to 0.8 mm. One specimen dark brown; both speci- 

 mens incomplete with up to eight setigers. Prostomium rectangular, with 

 two pairs of large, lentigerous eyes, anterior pair larger and farther 

 apart (Figure 28-32a). Antennae missing, base of median antenna arising 

 medially on prostomium. Palps with fairly long bases and styles. Nu- 

 chal organs as large, curved ridges al >np lateral and posterior margins 





