HYDROIDA 



31 



Corymorpha nutans M. Sars. 

 1835 Coryiiiorplia nutans^ M. Sars, Beskrivelser og lagttagelser p. 7, PI. r, Fig. 3. 



The In diocaulns, when extended, attain.s a height of 100 nun. It is broad at the basis, attached 

 to the substratvnii by numerous rhizoids, and tapering u])\vards till it readies its least breadth closely 

 below the polyp. The basis of the polyp is broad and surrounded by a proximal whorl consisting of 

 up to 50 tentacles, which, when extended, attain a length of 30 nun. The distal tentacles are small 

 and placed round the orifice in a main whorl composed of several irregular circles quite closely set 



The gonophores are developed into free medusae with four radial canals, one well-developed 

 tentacle and three rudimentary ones. The gonophores are developed on 15 — 20 blastostyles, arising 



._.! 000 m. 



2000/77. 



Text-fig. G. T]ie habitat ot Corymorpl:a nutans in the Nortliern .Atlantic. 

 (In the hatched regions the litteratiire denotes a scattered, allthough common occurence). 



closely above the proximal whorl of tentacles. The blastostyles bear small alternating branches, each 

 provided with a large number of gonophores. 



Material : 



Iceland, 16 minutes N. W. Akranes, depth 26—30 fathoms (a couple of )oung pol3'ps). 



The occurrence of the species is typically boreal. It is indigenous to the middle parts of the 

 littoral region. Towards the north it goes along the coast of Norway as far as Lofoten and towards 

 the south it penetrates to the northern parts of France. The species is recorded by Jiiderholm (1909) 

 from Matotschkin Schar (Nova Zembla) at the depth of between 2 and 5 fathoms. This find is most 

 peculiar and mysterious. Corynnorpha nutans occurs not rarely in the North Sea, and I think Hart- 

 laub (1907) is right in supposing the specimen from the North Sea recorded by me (1905) as a Cory- 



