Exogone dispar (Webster, 1879) 

 Figures 30-35, 36a-e 



Paedophylax dispar Webster, 1879:23, pi. 4, fig. 49, pi. 5, figs. 50-55. 



Exogone dispar — Hartmann-Schrbder, 1971:170. 



Exogone dispar — Day, 1973:33. 



Exogone dispar — Westheide, 1974:106, figs. 48A-H, 49A-D. 



Exogone dispar — Gardiner, 1976:132, fig. llf-i. 



Exogone dispar — Perkins, 1981:1090. 



MATERIAL EXAMINED: 

 Gulf of Mexico BLM-0CS: 



S0FLA 22-11/80 (1 spec, USNM 75286), 24E-7/81 (6 spec, USNM 89896), 

 28-11/80 (1 spec, USNM 75287); MAFLA 2207J-8/77 (2 spec), 2207K-8/77 

 (1 spec), 2422J-7/76 (8 spec), 2533B-6/75 (1 spec), 2533-7/75 (1 

 spec, USNM 55819); CTGLF 03-1/79 (1 spec); STOCS 1/IV-1 F/76 (1 spec, 

 USNM 75215), 1/IV-5 F/76 (1 spec, USNM 75216), 4/IV-5 Sp/76 (2 spec, 

 USNM 75218), 4/IV-2 F/76 (1 spec, USNM 75217); IXT0C S18-3 12/80 (1 

 spec, USNM 75130), S18-5 12/80 (1 spec, USNM 75131). 

 Supplementary Material: 



Virginia — M. Pettibone ID. (USNM 27562, 3 types). 



Florida — Tampa Bay, Sta. 16-17, 9 m, J. Taylor and T. Perkins ID. (2 

 spec, USNM 60478). 

 DESCRIPTION: 



Length, to 5.0 mm (previously reported to 9 mm); width, 0.2 mm (previ- 

 ously reported to 0.5 mm). Body small, thread-like; complete specimens 

 with up to 38 setigers. Prostomium rectangular with two pairs of len- 

 tigerous eyes in trapezoidal arrangement. Median antenna fusiform, 

 shorter than palps; lateral antennae small, ovoid (Figure 30-36a). 

 Palps completely fused dorsally. Nuchal organs as inconspicuous slits 

 between prostomium and peristomium lateral to eyes. Tentacular, dorsal, 

 and ventral cirri ovoid; dorsal cirri present on all setigers. Anal 

 cirri paired, long, cirriform. Superior simple seta distally blunt with 

 faint serrations near tip, present from setiger 1; becoming somewhat 

 bent posteriorly (Figure 30-36b). Composite setae including 1-2 supe- 

 rior spinigers (Figure 30-36c) per fascicle, and short-bladed bidentate 

 falcigers with pronounced subterminal tooth (Figure 30-36d). Inferior 

 simple seta bifid, present on far posterior setigers (Figure 30-36e). 

 Pharynx extending to setigers 3-5, dorsal tooth subterminal. Proventri- 

 cle extending from setigers 3-6 to 4-7, with 18 (16-21) muscle cell 

 rows. Embryos attached to ventrum of female beginning on setigers 14- 

 17; gametes of male beginning in setigers 10-11. 



PREVIOUSLY REPORTED HABITAT: Low water to 5023 m; shells, stones, sand, 

 coral, pilings. 



GULF OF MEXICO BLM-OCS OCCURRENCE: Common in northern Gulf (Figure 30- 

 35); 10-189 m; coarse to fine-very fine sand, silty fine to very fine 

 sand, clayey to sandy silt, silty clay. 



DISTRIBUTION: Arctic, North Pacific, North Atlantic, Maine to Florida, 

 Gulf of Mexico, Alaska to Mexico, Galapagos, South Japan, South Africa. 



30-43 



