MATERIAL EXAMINED: 

 Gulf of Mexico BLM-OCS: 

 SOFLA 25D-7/81 (1 spec, USNM 75319). 

 Supplementary Material: 



North Carolina — Wrightsville Beach, Banks Channel, in burrow of 

 Notomastus lobatus , E. Powell and H. Wilson colls., S. L. Gardiner ID., 

 July 1974 (2 spec, USNM 52892), Aug. 1974 (6 spec, USNM 52893), Feb. 

 1975 (5 spec, USNM 52894). 

 DESCRIPTION: 



Length, 2+ ram (previously reported to 9 mm); width, 0.5 mm (previously 

 reported to 1.4 mm). Body brownish in color; BLM-OCS specimen incom- 

 plete with 14 setigers. Prostomium oval, with two pairs of lentigerous 

 eyes (Figure 28-28a). Lateral antennae subulate, arising on anterior 

 margin of prostomium; median antenna much smaller, digitiform, arising 

 medially on prostomium. Palps shorter than lateral antennae. Nuchal 

 organs as white lobes lateral to prostomium. Tentacular and dorsal 

 cirri smooth or indistinctly articled distally. Parapodia biramous 

 starting on setiger 1, with small notopodia below dorsal cirrophores, 

 and well-developed neuropodia (Figure 28-28b). Ventral cirri clavate, 

 arising near tips of neuropodia. Notosetae of four kinds: I) relatively 

 short, blunt-tipped, spiked setae (Figure 28-28c), most numerous on 

 setiger 1; 2) spiked setae with long, fine tips (Figure 28-28d), most 

 numerous notosetae after setiger 1; 3) single, dentate acicular seta 

 (Figure 28-28e); 4) 2-3 fine-tipped, serrate setae (Figure 28-28f). 

 Furcate notosetae absent. Neuropodial falcigers slender, with long 

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

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

 length ratio 5.7-8.1:1. Pharynx extending to setigers 2-4, margin 

 surrounded by ten small papillae. 



REMARKS: Previous accounts of G_. vittata have not described the dif- 

 ferent kinds of notosetae. 



PREVIOUSLY REPORTED HABITAT: Intertidal to 55 m; rocks, shells, in 

 burrow of the capitellid Notomastus lobatus. 



GULF OF MEXICO BLM-OCS OCCURRENCE: Single record off southern tin of 

 Florida (Figure 28-27); 24 m; silt/clay. 

 DISTRIBUTION: Maine to North Carolina, southern Florida. 



Genus Amphiduros Hartraan, 1959b 



TYPE SPECIES: Amphidromus setosus Hessle, 1925. 



REFERENCES: 



Hessle, 1925:26 (as Amphidromus ). 



Fauchald, 1977a:75. 



DIAGNOSIS: Prostomium with three antennae and two biarticulate palps. 



Median antenna attached medially. Eight pairs of tentacular cirri. 



Parapodia biramous, with simple notosetae and composite neurosetae. 



Pharynx distally fimbriated, jaws absent. 



Key to the Gulf of Mexico BLM-OCS Species of Amphiduros 



la. Spiked notosetae (Figure 28-30e) tapering to long, fine tips. . . . 

 Amphiduros sp. A, p. 23-34 



28-31 



