PLATE 12 



Fig. 21. Head of Scolecolepis alaslensls. X 5. 



Fig. 22. l^arapodium from region of twenty fifth somite, of Scolecolepsis 



alaskensis. X 5. 



Fig. 23. Head of Polydora californica. X 28. 



Fig. 24. Seta from first neuropodium of Polydora californica. X 280. 



Fig. 25. Third parapodium ot Polydora californica. X 68. 



Fig. 26. Hook from sixth somite of Polydora californica. X 185. 



Fig. 27. Second form of hoolv from sixth somite of Polydora californica, 

 X 185. 



Figs. 28 and 29. Two views of a ventral hook from somite behind the 

 sixth, of Polydora californica. X 185. 



Fig. 30. Seta from fifth setigerous somite of Streblosoma crassibranchiata. 

 X 280. 



Fig. 31. Uncinus from Streblosoma crassibrancMata. X 560. 



Fig. 32. Ventral hooks of Trophonia minuta. X 68. 



Fig. 33. Notopodial hook of Trophonia inflata. X 68. 



Fig. 34. Head of Ophelina magna. X 10. 



Fig. 35. Seta from first setigerous somite of Ophelina magna. X 185. 



Fig. 36. Fourteenth parapodium of Ophelina magna. X 14. 



Fig. 37. Head of Ophelina mucronata. X 45. 



Fig. 38. Gills of Ophelina mucronata. X 45. 



Fig. 39. Dorsal collar seta of Laonome oculifera. X 185. 



Fig. 40. Ventral collar seta of Laonome oculifera. X 185. 



Fig. 41. Ventral thoracic seta of Laonome oculifera. X 185. 



Fig. 42. Thoracic uncinus of Laonome oculifera. X 185. 



Fig. 43. Pennoned seta from thorax of Laonome oculifera. X 185. 



Fig. 44. Collar seta of Branchiomma disparoculatum. X 185. 



Fig. 45. Spatulate thoracic seta of Branchiomma disparoculatum. X 185. 



Fig. 46. Uncinus from thorax of Branchiomma disparoculatum. X 185. 



Fig. 47. Collar seta of Hydoides sp. X 185. 



Fig. 48. Terminal plate of operculum of Hydroides sja. X 8. 



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