15 Middle parapodia with small accessory branchiae. Anterior 



branchiae fused to notopodial lamellae | Prostomium pointed. 



(Dispio)] D. iiiici)iuta 



15' Middle parapodia without accessory branchiae. Anterior bran- 

 chiae partly fused or free from notopodial lamellae 16 



16 Prostomium rounded or e.\])anded in front (Spia) 17 



UV Prostomium with distinct lateral peaks (Mdhicdcci-ds) No N.C. record 



17 Prostomium expanded in front and bears several eyespots. 



No occipital tentacle. Hooded hooks in neuropodia from 



setiger 28-;'>2 S. ninltinc/ilittn 



17' Prostomium rounded in front and bears 4 eyespots. Occipital 

 tentacle present or absent. Hooded hooks in neuropodia 

 from .setiger 10-11 18 



18 No occipital tentacle. Head with brown markings. Hooks bi- 



dentate to tridentate, 6-9 per foot S. p( ttihoiicac 



18' Occipital tentacle present. Head without brown markings. 



Hooks always bidentate, 15-20 per foot S. sctosu 



19 One pair of smooth branchiae on setiger 1. A dorsal crest 



across setiger 2. (Strchlospio) S. houdicti 



19' Three pairs of pinnate branchiae (or scars thereof) on setigers 

 1 to 3. A dorsal crest across setiger 1. [Peristome folded 

 round sides of prostomium iPinvpi-ioiioKpio)] P. puniata 



20 Posterior notopodia with hooded hooks 21 



20' Posterior notopodia without hooded hooks 29 



21 Branchiae fused to notopodial lamellae anteriorly, becoming 



sei)arate later and continuing to jjosterior segments. Pygid- 



ium with a cushion below anus (Smh l( pi^') S. xqinn))ata 



21' Branchiae free from notopodial lamellae anteriorly and con- 

 fined to anterior part of body. Pygidium with anal cirri 22 



22 Prostomium with an occipital tentacle. Branchiae never pin- 



nate (Ain}id(:<) [Hooded hooks bidentate] A. sp. 



22' Prostomium without an occipital tentacle. Branchiae either 



pinnate, smooth or both iPrioiiospIo) 23 



23 All branchiae smooth and number 4 to 40 pairs (subgenus 



Miiinspki) 24 



23' At least one pair of branchiae pinnate and number 4 or 5 pairs 25 



24 About 6 pairs of long branchiae. Hooded hooks multidentate. 



Genital pouches between middle neuropodia of adults P. (M.) cirnftra 



24' About 11 pairs of normal branchiae. Hooks with one tooth 



above main fang. No genital pouches P. (M-) clrrohnnicliiata 



25 Five pairs of branchiae with 1st, 4th, and 5th pinnate. [No 



dorsal crest across setiger 7] P- hvtcrubranchia 



25' Four pairs of branchiae 26 



67 



