25 



besat med Polyper. SStrax ovenfor Basaldelen deler Hoved- 

 stammen sig i to, hvoraf den ene Stamme er meget kortere 

 end den anden, Fig. 55. Fra den korte Stamme udgaar 

 kun en Gren, der er tyk og kort, og hvis bredere Ende 

 indtages af Polyper. Den længere Stamme har 4 — 5 

 Grene, hvoraf den nederste er l() mm lang, omtrent 5""" 

 bred paa Midten og temmelig tæt besat med Polyper. der 

 gruppere sig paa den noget afrundede Ende; de øvrige 

 Grene ere meget kortere; den øverste er omtrent 2"™ lang 

 og dannes egentlig derved, at 3 — 4 Polyper ere sammen- 

 voxede ved Granden, Eig. 55. Fra selve Hovedstammen 

 udgaa dels enkelte, dels 2—3 ved Granden sammenvoxede 

 Polyper; det samme finder ogsaa Sted overalt paa den 

 lange Stamme, som dels derved, dels ved de tæt sluttende 

 Grene saagodtsom ganske dækkes. Stammen og Grenene 

 ere haarde. læderagtige og meget rige paa Kalkafsætninger. 



Polypcellerne, der ere korte, cylindriske og meget 

 kalkholdige, staa stundom et Stykke fra hverandre, men 

 som oftest tæt sammen og kunne kun iagttages, naar 

 Polyp erne ere halvt indtrukne ; ere disse fuldt udstrakte, sees 

 Cellen at gaa over i Polypen uden anden synbar Grænse, 

 end at Spiklerne ligge noget tættere i Cellen, der, som 

 tidligere paavist, egentlig udgjør den bagerste Del af 

 Polypkroppen. 



Polyperne ere indtil 12'"™ lange, næsten cylindriske, 

 lidt indknebne imellem For- og Bagkrop, Fig. 56. Denne 

 sidste er omtrent 5""" lang, smalner lidt af, hvor den gaar 

 over i Cellen, er tæt besat med Spilder, der ligge paatvers 

 og synes ikke at være delte i Rækker, saaledes som Til- 

 fældet er paa Forkroppen, som er omtrent 3"™ lang og 

 har 8 stærke Længderibber, dannede af Spilder og adskilte 

 ved ligesaa mange dybe Furer, der ogsaa ere forsynede 

 med Spilder, Fig. 56. Tentaklerne ere omtrent 4" m lange 

 og have paa hele deres aborale Side et stærkt Spikelpantser, 

 som strækker sig udover de temmelig lange Pinnuler. Den 

 stærke Spikelbeklædning gjør, at Polyperne ere temmelig 

 uigjennemsigtige 1 . 



1 En Polyp havde i sin Bagkrop, som syntes at være sygelig, 

 produceret en meget smuk Perle, der havde et Knappenaalshoveds 

 Størrelse, var fuldstændig rund, hvidgul med et smukt Farvespil som 

 en ægte Muslingperle, men adskilte sig dog fra denne derved, at 

 den var halv gjennemsigtig. Jeg berører dette for at antyde, at 

 der gives andre Dyr end Molluskerne, som kunne producere Perler. 



Den norske Nordhavsexpedition. D. C. Danielssen : Alcyonida, 



diminishes in thickness, a little, towards its rounded 

 summit, which is closely beset with polyps. The parent 

 stem divides itself, immediately above the basal part, into 

 two parts, one of which is much shorter than the other 

 (fig. 55). From the short stem, a single branch issues, 

 which is thick and short, and its broad extremity is occu- 

 pied by polyps. The long stem has 4 — 5 branches, of 

 which the lowest one measures 10""" in length, and about 

 h mm in thickness at the middle ; it is pretty closely beset 

 with polyps, which group themselves together on the some- 

 what rounded extremity; the other branches are much 

 shorter ; the uppermost one measures about 2 ram in length and 

 is, in fact, formed by the concretion together at their base 

 of 3 — 4 polyps (fig. 55). From the parent stem itself, 

 there issue, sometimes single, sometimes 2 — 3 polyps con- 

 creted together at the base, and the same thing occurs 

 throughout the long stem which, partly, from that cause 

 and, partly, from the close placing of the branches, is al- 

 most quite covered. The stem and the branches are hard, 

 coriaceous, and very rich in calcareous deposits. 



The polyp-cells are short and cylindrical, and very 

 calcareous; they are placed, occasionally, a little distance 

 apart from each other, but most frequently close to each 

 other, and can only be observed when the polyps are semi- 

 retracted. When the polyps are fully extended, the cell 

 is seen to pass over into the polyp, without other notice- 

 able margin than that the spicules lie somewhat closer in 

 the cell, which, as already shewn, really constitutes the 

 posterior part of the polyp body. 



The polyps measure up to 12 mm in length, and are 

 nearly cylindrical; they are someAvhat constricted between 

 the anterior and posterior body (fig. 56). The latter mea- 

 sures about 5"™ in length, and diminishes a little in thick- 

 ness at the point where it passes over into the cell; it is 

 closely beset with spicules placed transversally, and which 

 do not appear to be arranged into series like what is the 

 case on the anterior body; that — the anterior body — 

 measures about 3 mm in length, and has 8 strong longitudinal 

 ribs formed of spicules, separated by the same number of 

 deep grooves, which also are furnished with spicules 

 (fig. 56). The tentacles measure about 4 mm in length and, 

 on their entire aboral side, have a strong spicular sheathing 

 which extends itself over the rather long pinnules. The 

 strong spicular covering causes the polyps to become pretty 

 opaque 1 . 



1 One polyp had. in its posterior body which appeared to be 

 morbid, produced a very beautiful pearl about the size of a > pins 

 head, and completely globular, whitish yellow in colour, with a fine 

 play of colours like a genuine mussel-pearl, but differing, however, 

 from that in being semi-transparent. I mention this in order to in- 

 dicate that there are other animals besides the molluscs which can 

 produce pearls. 



