Gatty Marine Lahoralory, St. Andrews, 67 



posterior hook almost identical witli the foregoing, so that 

 its distribution may be extensive, thongh the absence of 

 branchice and other parts in the Arctic fragment leave a 

 margin of doubt. 



EXPLANATIOX OF THE PLATES * 



Platk I. 



Fiy. 1. Dorsal aspect of the region of tlie collar and tlie branchial base 



in Sdbella mnrrcuii, sp. n,, from H.M.S. ' Kuight Errant.' 



Enlarged under a lens. 

 Fig. 2. Lateral view of the same region, 

 Fiff, 3. Slightly winged dorsal bristle of the longer type. x Zeiss 



00. 4, obj. D. 

 Fig. 4. Spatulate bristle with filament at the tip. Ditto. 

 Fig. 5. Posterior bristle. 

 Fig. 6. Remarliable anterior hook with a differentiation of the posterior 



border beliind the prow and a greatly elongated shaft. 



X oc. 4, obj. D. 

 Figs. 7, 8, Minute bristles accompanying the long anterior hooks. 



X 450 diam. 

 Fig. 9. Posterior hook of the same. X oc. 2, obj. F. 

 Fig. 10. Anterior hook of Sahella soiitherni, sp. u., with long basal 



process, x oc. 4, obj. D, with 2-in. draw-tube. 

 Fig. 11. Posterior hoolv of the foregoing with abbreviated base. X oc. 4, 



obj. D, with 1-in. draw-tube. 



Plate XL 

 Fig. 1. Anterior winged bristle of Sabella southerni, ' Knight Errant.' 



X oc. 4, obj. D, with 1-in. draw-tube. 

 Fig. 2. Posterior bristle with longer tip. Ditto. 

 Fig. 3. Spatulate bristle of the same. X oc. 4,j obj. D, with 1-in. 



draw-tube. 

 Fig. 4. Anterior winged bristle of Chone duneri, Malmgren. x oc. 4, 



obj. D, with 1^-in. draw-tnbe. 

 Fig. 5. Spatulate bristle of the foregoing. X oc. 4, obj. F. 

 Fig. 6. Anterior hook. X oc. 4, obj. D. 

 Fig. 7. Posterior hook, x oc. 4, obj. F. 

 Fig. 8. Posterior hook of Chone fauveli, St. Andrews (? marked variety 



of C. duneri). 

 Fig. 9. Posterior hook of typical Chone infundibuliformis, Kr., from 



Greenland. X oc. 4, obj. D. 



Fig. 10. Posterior hook of Chone reagi, sp. n. X oc. 4, obj. F. 



Fig. 11. Anterior hook oi Euchone lawrencii, sp. n. ? X 500 diam. 

 Fig. 12. Posterior hook. X 500 diam. C^ou-e. ^ »y '»*«•' "■ 



Fig. 1-3. Longer winged bristle of Sabe^t nordeh^ioldi, sp. n. X 450 



diam. 

 Fig. 14. Spatulate bristle. X 450 diam. 

 Fig. 15. Anterior hook of the same. X 450 diam. 



Plate III. 



Figs. 1, 2. Minute cuspidate bristles accompanying the anterior hooks of 

 Sabella southerni. X oc. 4, obj. D, with draw-tube. 



* I am indebted to the Carnegie Trust for the majority of these 

 figures. 



5* 



