BURNE : ANATOMY OF HANLKYA ABYSSOKUM. / 



lio seen on referring to Fig. I, that in its anterior part, in fact 

 till it arrives at the region of the gills (confined in this species to the 

 hinder part of the hody), it is circular in cross-section ; at that point 

 it hecomes distinctly larger, broader, and flatter, and though this 

 enlargement is not very striking, yet it is sufficiently so to be 

 suggestive of a tendency to concentration in this region, a tendency 

 that may be due, no doubt, to the restricted area occupied by the gills. 





'XS' 



M 

 ;ssr. 



>ir 



\ y^. 





JGzr 



■X!y^ 



Fig. I.— Posterior portion of the right lateral uerve-cord of Ilanlci/a abyssormn. 

 X 8 (reconstructed from sections) . ;.«. lateral nerve-cord, m.n mantle 

 nerves, i-xvi. external branchial nerves, i'-xvi'. internal branchial 

 nerves. 



We will now turn to the epithelial covering of the efferent branchial 

 blood-vessel. In spite of the necessarily imperfect condition of such 

 delicate tissues, in specimens preserved merely in spirit, a transverse 

 section makes it sufficiently clear that its structure does not entirely 

 tally with the description given by Haller.^ Apart from the enormous 



1 Lor. cit. p. 26. 



