POLTCHAETE WORMS, PART 1 101 



Distribution. — Davis Strait, off Newfoundland to south of Massa- 

 chusetts, south Iceland, off Ireland, Azores, Mediterranean, Arabian 

 Sea, South Atlantic, Antarctic, northeast Pacific (off California), 

 South Pacific (New Zealand). Surface to perhaps deep abyssal 

 « 1,055 fathoms). 



Family Hesionidae 



Body small to moderate in size. Prostomium distinct, suboval to 

 subquadrangular, usually with 4 eyes (0, 2, or 4), 2 or 3 antennae, 2 

 palps (may be biarticulate). Tentacular segments 1 to 4, achaetous, 

 more or less distinct, with 2 to 8 pairs of tentacular cirri. Parapodia 

 biramous or subbiramous; notopodia may be reduced to acicula in the 

 cirrophores of the dorsal cirri, with notosetae simple or lacking. 

 Neiu"0setae compound, with terminal blades long to short. Dorsal 

 cirri short to long, smooth or more or less distinctly articulated; 

 ventral cirri shorter, about the length of the neuropodia ; 2 anal cirri. 

 Carnivorous. Proboscis cylindrical, eversible, with or without mar- 

 ginal papiUae, with or without horny jaws. Often conspicuously and 

 brilliantly colored. 



A number of hesionid species show commensalistic tendencies. 

 Many are highly active and irritable, darting back and forth when 

 touched. They may break up rather easily; some swim readily. 



Key to the New England Genera of Hesionidae 



1. Tentacular cirri 6 pairs on 3 distinct segments (segments not crowded or 



reduced (fig. 27a)). With anal plate in addition to short anal cirri, an 

 entire flattened disc (fig. 27c) or bilobed plate (fig. 276). Prostomium with 



2 rudimentary eyes or eyes lacking, 2 lateral antennae, a median occipital 

 antenna, 2 palps (fig. 27a) Microphthalmus 



Tentacular cirri 6-8 pairs on 3 to 4 anterior segments, some of which are 

 crowded and reduced dorsally. Without anal disc, with a pair of long 

 anal cirri only (fig. 296). Prostomium with 4 eyes, 2 lateral antennae, 2 

 palps, with or without a median antenna (when present, anterior, not 

 occipital; fig. 28a) 2 



2. Prostomitim with a short median anterior antenna, with biarticulate palps 



(fig. 28a, c). Notopodia rudimentary, reduced to acicula and few simple 



capillary notosetae (fig. 28,6, d) 3 



Prostomium without median antenna (fig. 29a). Tentacular cirri 6 pairs . 4 



3. Tentacular cirri 6 pairs Podarke 



Tentacular cirri 8 pairs Gyplis 



4. Palps biarticulate. Notopodia rudimentar}^, reduced to acicula in cirrophores 



of dorsal cirri, with or without few capillary notosetae; neuropodia with 



3 conical lobes (fig. 28e) Nerrimyra 



Palps unjointed (fig. 29a). Notopodia forming a distinct lobe with capillary 



notosetae; neuropodia diagonally truncate, without conical lobes (fig. 

 29c) Parahcsiune 



