8a. Notosetae present 9 



8b. Notosetae absent 12 



9a. Notosetae represented by a stout, hooked spine (Figure 28-24c), 

 first appearing around setiger 10 ' Hesiospina, p. 28-25 



9b. Notosetae capillary, acicular or furcate, first appearing on seti- 

 gers 2-5 10 



10a. Jaws present Leocrates** 



10b. Jaws absent 11 



11a. Margin of pharynx smooth or papillose (Figure 28-26a) 



Gyptis, p. 28-27 



lib. Margin of pharynx fimbriated (Figure 28-30a) 



Amphiduros, p. 28-31 



12a. Palps absent Hesione, p. 28-36 



12b. Palps present Kef ersteiaia, p. 28-38 



*Not represented in BLM-OCS collections, but known from inshore and 

 estuarine areas of the Gulf of Mexico (Pettibone, 1963:109). 

 **Not represented in BLM-OCS collections, but found on Gulf of Mexico 

 coral reefs (pers. obs. of author). 



Genus A 

 Figures 28-1, 2a-d 



MATERIAL EXAMINED: 

 Gulf of Mexico BLM-OCS: 



SOFLA 12C-11/80 (1 spec, USNM 75329), 33A-7/81 (3 spec, USNM 71775); 

 MAFLA 2957D-8/77 (2 spec). 

 DESCRIPTION: 



Length, to 2.0 mm; width, to 0.7 mm. Body minute; complete specimens 

 with up to 20 setigers. Prostomium roughly trapezoidal, widest poste- 

 riorly, with subulate lateral antennae, biarticulate palps, and small 

 midanterior facial tubercle (Figure 28-2a). Median antenna absent. 

 Eyes poorly developed or absent. Nuchal organs as large, paired, cili- 

 ated patches at postectal corners of prostomium. Four pairs of indis- 

 tinctly articled tentacular cirri, dorsal pairs longer and stouter than 

 ventral pairs. Only second tentacular segment visible dorsally. Para- 

 podia subbiramous, notopodia represented by small acicular lobe at base 

 of dorsal cirri, neuropodia well-developed with pointed acicular lobe 

 and conical subacicular lobe (Figure 28-2b). Dorsal cirri short, digit- 

 iform, extending slightly beyond tips of neuropodia anteriorly. Ventral 

 cirri shorter, tapered or subulate. Notopodia with 1-3 extremely slen- 

 der capillary setae (Figure 28-2c) starting on setiger 2. Neuropodial 

 falcigers long-bladed with minutely hooked tip and subapical spine 

 (Figure 28-2d); blades graded in length from upper to lower positions in 

 fascicle, blade-length ratio 2.6-5.5:1. Pygidium rounded with two 

 short, digitiforra anal cirri. Pharynx extending to setigers 4-5, margin 

 surrounded by numerous small papillae, jaws not observed. One specimen 

 with sacs of small, round cells (oocytes?) at bases of parapodia. 



28-5 



