PLATE XL. 



Fig. I. 



2. 



3- 

 4- 

 5- 



6. 



7- 



9- 



lO. 



II. 



12. 



13- 



14. 



i.S- 

 16. 



17- 



18. 

 19. 



20. 



21. 



22. 



23- 

 24. 



25- 

 26. 



27. 

 28. 

 29. 



Spirorbis abnormis sp. nov. , p. 245. Front view of calcareous plate 



from operculum of a young specimen. 

 Side view of same. 



Hyalopomatopsis occide7italis sp. nov., p. 229. Abdominal seta. 

 Spirorbis. variabilis sp. nov., p. 238. Caudal seta. 

 Spirorbis spirorbis (Linne), p. 262. Collar seta of specimen from 



Gloucester, Massachusetts, back view. 

 Odd seta from third thoracic fascicle, about ^ view. 

 Spirorbis spiriUum (Linn^) var. /«c/</«5 (Montagu), p. 243. Caudal 



seta of specimen from Pacific. 

 Spirorbis spirorbis (Linn^), p. 262. Entire seta from one of a chain 



of embryos taken from tube. 

 Spirorbis similis sp. nov., p. 242. Collar seta. 

 Spirorbis quadrangularis Stimpson, p. 241. Collar seta of specimen 



from Greenland, about ^ view. 

 Curved abdominal seta. 

 Spirorbis spirorbis (Linn^), p. 262. Collar seta from another 



specimen. 

 Seta from second or third thoracic fascicle. 

 Side view of odd seta from third thoracic fascicle. 

 Caudal seta. 

 Spirorbis tnarioni Caullery and Mesnil, p. 239. Collar seta of specimen 



from Mexico. 

 Spirorbis similis sp. nov., p. 242. Back view of operculum of a young 



specimen, showing calcareous plate. 

 Front view of same. 

 Spirorbis incongruus sp. nov., p. 241. Front view of calcareous plate 



from operculum. 

 Back view of same. 

 Spirorbis quadrangularis Stimpson, p. 



third thoracic fascicle, in profile. 

 Hyalopomatopsis occidentalis sp. nov., p 



much spread. 

 Spirorbis quadratigularis Stimpson, p. 241 



from the Banks, Atlantic Ocean. 

 Spirorbis granulafus Linn^, p. 247. Collar seta of specimen from the 



Banks, Atlantic Ocean. 

 Spirorbis sp. Collar seta. 

 Spirorbis quadrangularis Stimpson, p. 241. Base of collar seta (blade 



broken) from specimen from Greenland. 

 Spirorbis cancellaius Fabricius, p. 248. Collar seta. 

 Spirorbis iticongrutis&p. nov., p. 241. Collar seta. 

 Spirorbis stimpsoni Verrill, p. 250. Odd seta from third thoracic 



fascicle. 



(338) 



241. Seta from second or 

 229. Collar seta, basal fin 

 Collar seta of specimen 



