422 Hjalmar Ditlevsen 



be retained. The only thing which in my opinion could definitely 

 settle the question, would be Ørsted's original specimens, but these 

 are unfortunatel}^ quite lost. 



Regarding the relation between the two species N. pelagica and 

 N. zonata, I am of the opinion after close comparison, that the fol- 

 lowing differences may be regarded as constant. N. pelagica never 

 has light transverse bands, which are more or less conspicuous in 

 iV. zonata. In N. pelagica the parapodial lobes are evenly rounded, 

 in Л^. zonata triangular, running out to a broad point, hi Л'^. pelagica 

 the end-leaf of the bristles provided with a short terminal joint are 

 shorter and more curved than in Л^ zonata. 



Hesionidæ. 



Castalia Fabricii (Mgrn.). 

 1867. Malmgren p. 32, C. arctica. 

 1878. Théel p. 87. 

 Localities: 



St. 18. Danmarks Havn 

 „ 23. 



„ 45. 

 Several specimens are present from these stations. 



Syllidæ. 



Syllis ГаЪпси Mgrn. 



1867. Malmgren p. 44. 



Locality : 



St, 91. Stormbugt 2—12 m. i^/g 08. 



There is only one specimen of this species, which was also found 

 by the Sverdrup Expedition and which I determined as belonging to 

 Sijllis Fabricii Mgrn. I have learnt later, that there is no specimen 

 of this species in the Stockholm Museum and that it would thus be 

 impossible to make certain of the identity. I follow Levinsen here 

 however, at least provisionally, who has retained Malmgren's S. Fa- 

 bricii for the same Greenland species (Levinsen I p. 248). 



Syllis incisa Fabr. 

 1867. Malmgren p. 44. 

 Locality: 



St. 57 a. Danmarks Havn 16 — 20 m. ^/s 07. 



There is one specimen from this locality. 



