8 Dorsal cirri of middle feet short and fusiform with about 15 



joints. Setae obviously bidentate S. (T.) hyalinu 



8' Dorsal cirri of middle feet at least as long as segmental 



breadth with more than 15 joints. Setae strongly bidentate 9 



9 Setae of posterior feet with secondary tooth stronger than 



apical one. Dorsal cirri with 25-40 joints S. (T.) nguhita caroUnae 



9' Setae of posterior feet with secondary tooth not stronger than 



apical one 10 



10 Dorsal cirri of middle segments alternately with 15 or 20 joints. 



Proventriculus extending over 7 to 9 segments S. (T.) alternata 



10' Dorsal cirri of middle segments alternately with about 30 and 



87 joints. Proventriculus extending over 5 to 6 segments S. (T.) proUfera 



11 Pharynx coiled. Body short with about 13 setigers. Large 



nuchal epaulettes (Antblyoaylli^^). [Six triscuspid marginal 



teeth] A.formosa 



ir Pharynx straight. Body long with many .setigers. No nuchal 



epaulettes 12 



12 Large knobbed acicula projecting from anterior feet. Pharynx 



without teeth (Streptosifllis). [Setae with flanged shaft- 

 heads and blades] S. arenae 



12' Acicula normal, not exposed. Pharynx with one or more teeth 13 



1.3 A large occipital flap. Pharynx with a ventr' 1 semicircle of 

 teeth halfway back {Odoutosyllis). [Setal blades very long 

 and strongly bidentate] 0. loiigiseta 



13' Occipital flap small or absent. Pharynx with a single anterior 



dorsal tooth and a smooth or denticulate margin 14 



14 Margin of pharynx denticulate iEusyllis). [Dorsal cirri ex- 



tremely long and first pair of ventral cirri lamellar] E. lumelUgera 



14' Margin of pharynx smooth 15 



15 One pair of tentacular cirri (Parapio)iot<ylH><) P. Iviigicirrata 



15' Two pairs of tentacular cirri iPio)iosyUis). [Superior setae 



with elongated blades and inferior setae with short blades 



with secondary tooth larger than apical one] P. cf. umga 



16 One pair of tentacular cirri 17 



16' Two pairs of tentacular cirri 21 



17 Dorsal cirri ovoid, minute; body surface without sticky papillae 



or adherent silt. (E.vogoiie) 18 



17' Dorsal cirri bottle-shaped or onion-shaped; body surface with 



sticky papillae and adherent silt {Sphaerot<yllis) 20 



18 Dorsal cirri on all setigers including second 19 



18' No dorsal cirinis on setiger 2. [Median antenna hardly longer 



than laterals] E. gemmifera 



27 



