Forord. 



De paa den norske Nordhavsexpedition indsamlede 

 Alcyonider ere ndelukkende Dybvandsformer, bløde Koral- 

 dyr, som for Størstedelen leve i det iskolde Vand. De 

 danne 9 nye Slægter, der alle ere henførte til Underfami- 

 lien Alcyoninæ, 33 nye Arter, hvoraf 2 tilhøre Slægten 

 Clavularia, 1 Slægten Sympodinm og 1 Slægten Nidalia 

 (Gray), samt endelig en ny Underfamilie, Organinæ, med 

 en ny Slægt og Ai^t. 



Af Alcyon ariernes store Dyregruppe tør vel Alcyo- 

 niderne være den, der er mindst udførligt bearbeidet af 

 Nutidens Zoologer, uagtet de baade ved sine elegante 

 Former og skjønne Farver kunne være tiltrækkende nok. 

 Men de ere meget fine, trække sig let sammen, for- 

 andre derved sin Form og ere tildels meget vanskelige 

 at holde længere Tid ilive, efterat de have forladt deres 

 naturlige Hjem; især gjælder dette sidste Dybvandsformerne, 

 hvilket Alt gjør, at der til Observationerne knytte sig 

 mange Vanskeligheder, som blive alt større og større, jo 

 længere Dyrene have været opbevarede i Alcohol. 



Ihvorvel jeg som Medlem at den norske Nordhavs- 

 expedition var den, der indsamlede de nævnte Koraldyr, og 

 saaledes havde Anledning til at observere dem levende, 

 maa jeg dog tilstaa., at de Observationer, jeg ombord kunde 

 anstille mecl Hensyn til disse Dyr, vare yderst ufuldkomne. 

 Skibets Bevægelse, der ofte var meget stærk, gjorde, at 

 de Dyr, som kunde trække sig sammen, holdt sig indtrukne 

 i mange Dage, saa jeg blev nødsaget til at kaste dem i 

 Alcohol, for at de ikke skulde gaa tilgrunde ; selv de Dyr, 

 der ikke vare retraktile, bøiede dog sine Tentakler saa 

 stærkt ind mod Skiven, at denne ganske blev skjult, og da 

 de efter flere Dages Forløb (indtil 10 Dage) ikke længere 

 viste noget Livstegn, maatte ogsaa disse opbevares paa 

 Alcohol uden. at være tilfredsstillende observeret. 



Den mere indgaaendeUndersøgelse 'af Materialet er saa- 

 ledes hovedsagelig foretaget paa Spiritusexemplarer, og det 



Den norske Nor dliavsexp edition. D. C. Danielssen: Alcyonida, 



Preface, 



The Alcyonids collected during the Norwegian North- 

 Atlantic Expedition are exclusively deep-sea forms; soft 

 coral animals, that principally exist in the ice-cold waters. 

 They form 9 new genera, which are all assigned to the sub- 

 family Alcyoninæ; 33 new species, of which two belong to 

 the genus Clavularia, one to the genus Sympoclhim, and 

 one to the genus Nidalia (Gray) and, finally, a new sub- 

 familæ Organinæ, with a new genus and species. 



Of all the extensive animal-groups of the Alcyonaria, 

 that of the Alcyonids is probably the one least minutely 

 treated by modern Zoologists, notwithstanding that, both 

 by their elegant forms and beautiful colours, they are suf- 

 ficiently attractive. They are however very delicate, quickly 

 shrink together, changing, thus, their form, and are often 

 very difficult to retain any length of time alive after 

 removal from their natural home ; this last feature is spec- 

 ially applicable to the deep-sea forms; all this combines 

 to surround the observations with difficulties, which be- 

 come greater and greater the longer the specimens have 

 been preserved in alcohol. 



Although I was the member of the Norwegian North- 

 Atlantic Expedition who collected the coral animals referred 

 to, and had thus the opportunity of observing them alive, 

 yet I must confess that, the observations I could undertake 

 on board ship, in relation to these animals, were highly 

 incomplete. The tossing of the ship, which frequently was 

 very great, caused those animals capable of shrinking 

 together to remain contracted for many days, so that at 

 last I was obliged to place them in alcohol in order that 

 they might not be altogether lost. Those animals, even,, that 

 were not retractile still curved their tentacles so greatly 

 in to the disk that it was completely hidden, and as 

 after the lapse .of several clays (as many as 10 days), they 

 no longer showed signs of life, they also required to be 

 placed in alcohol without having been satisfactorily observed. 



The more detailed examination of the material is, 

 therefore, undertaken with the specimens preserved in 



