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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 98 



This differs from E. antennata Savigny in that the branchiae 

 diminish in size after the thirtieth segment ; the peristomial cirri are 

 not annulated ; the composite setae are distally bifid (fig. 3, a). 



Fig. 3. — Species of Eunice, Polydora, Cirratulus, and Metachone. 



a-b, Eunice aedificatrix : a, composite seta, with bifid tip, X T 95; b, simple, 

 uncinigerous seta, with trifid tip, X 195. 



c-k, Polydora tricuspa: c, a planktonic larva, in dorsal view, showing char- 

 acteristic pigmented pattern, rounded prostomium, paratrochs on segments VI, 

 VIII, XI, and XIV, and parapodial glands in segments VIII to XII, somewhat 

 depressed under cover slip, X 60 ; d, a falcigerous and a tricuspid seta, unworn, 

 from the dorsal fascicle of the 6th segment, X430; e and /, worn tricuspid 

 setae from the same fascicle as that shown in figure d, X 430 ; g, a worn falcate 

 seta from the same fascicle, X430; h, a hooded crotchet for a neuropodium 

 posterior to the 8th segment, X 430 ; i, stout hooks from planktonic larva, X 57o; 

 j, fascicle of capillary setae ventral to the hooks shown in i, X 570 ; k, anterior 

 end of a 16-segmented larva showing small setal fascicle in segment I, and 

 reduced neuropodial fascicle in II, depressed under cover slip, X 180. 



/, Cirratulus niger: an uncinigerous seta from a median parapodium, X T 95- 



m-o, Metachone mollis: m, a spatulate notopodial seta, with minute mucron, 

 X 195: n, a thoracic uncinus, from a median thoracic parapodium, X 195 J °, 

 abdominal uncinus, from an anterior abdominal parapodium, X T 95- 



