flap large, roughly rectangular. Tentacular cirri long, smooth. Dorsal 

 cirri long anteriorly, thereafter alternating long and short. Ventral 

 cirri lanceolate, generally shorter than parapodia. Composite falcigers 

 numerous, short-bladed, bidentate; terminal tooth falcate, often larger 

 than subterminal tooth; with fimbriated sheath connecting blade to 

 shaft-head (Figure 30-80b,c). Acicula distally constricted, with minute 

 serrations surrounding small, pointed tip (Figure 30-80d). Pharynx 

 extending to setiger 5, with ventral arc of five recurved teeth (Figure 

 30-80e). Proventricle located in setigers 6-19, with about 87 muscle 

 cell rows. 



REMARKS: Odontosy His sp. A is similar to 0_. maculata Ushakov, 1950, 

 from the northeastern Pacific, in having a trepan of five or six ventral 

 teeth. It differs from the latter in having longer dorsal cirri and 

 bidentate falcigers with shorter blades superiorly (see Imajima, 

 1966:103). 



GULF OF MEXICO BLM-OCS OCCURRENCE: One station off Panama City, Florida 

 (Figure 30-79); 45 m; coarse sand. 



Genus Trypanosyllis Claparede, 1864 



TYPE SPECIES: Syllis zebra Grube, 1860a. 

 REFERENCES: 

 Imajima, 1966:235. 

 Day, 1967:253. 

 Fauchald, 1977a:84. 



DIAGNOSIS: Body usually dorsoventrally flattened with segments much 

 wider than long. Prostomium with three antennae; palps basally sepa- 

 rated. Nuchal organs as large, curved ridges along posterior border of 

 prostomium. Two pairs of tentacular cirri. Antennae, tentacular, and 

 dorsal cirri articled. Pharynx with terminal trepan of usually ten 

 teeth, with or without an additional midorsal tooth. 



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



la. Body large, adults up to several centimeters long; dorsum with 

 transverse brown stripes (Figure 30-82a); proventricle longer than 

 pharynx Trypanosyllis vittigera, p. 30-88 



lb. Body small, adults usually less than 1 cm long; dorsum without 

 transverse brown stripes; proventricle shorter than pharynx. . . 2 



2a. Blades of inferior falcigers unidentate to subbidentate (Figure 



30-84d,e) Trypanosyllis sp. B, p. 30-91 



2b. Blades of inferior falcigers bidentate (Figure 30-86c,e). ... 3 



3a. Antennae, tentacular and anterior dorsal cirri long, usually with 



more than ten articles (Figure 30-86a) 



Trypanosyllis parvidentata, p. 30-91 



3b. Antennae, tentacular and dorsal cirri short, usually with fewer 

 than ten articles (Figure 30-88a) 4 



4a. Pharynx up to twice as long as proventricle (Figure 30-88a); body 

 broad, flattened Trypanosyllis coeliaca, p. 30-93 



30-86 



