98 



udvendige Side fri, ikke sarnmenvoxet ved Basaldelen, 

 men gaar umiddelbart over i Sarcosomaet. Polyperne 

 kunne imidlertid trække sig noget sammen; men da de 

 ingen Celle have og heller ikke kunne trække sig ind i 

 Sarcosomaet, er det kun en Sammentrækning i sig selv. 

 Denne sker langsomt og paa den Maade, at den lange 

 Krop forkortes successivt, og Tentaklerne indkrænges 

 derefter, hvorfor en saadan sammentrukken Polyp kan 

 have de forskj elligste Former. Paa Grund af den Træg- 

 hed, hvormed Polyperne trække sig sammen, sees de aller- 

 fleste bestandig at være ude, endog paa Spiritus-Exem- 

 plarer. Æggene udvikles i hele Kropshulheden, saavel i 

 de peri- som hypogastriske Rum, og kunne ganske ud- 

 fylde disse. Axen stiv, rund, lige, 1 Mm. tyk, og oventil 

 tvers afskaaren. Stokken tilligemed Polyperne have i le- 

 vende Live en brunrød eller brunviolet Farve. 



Vi fandt den ved Molde paa en Dybde fra 30—60 

 Favne i lerholdig Sand. 



G. O. Sars har fundet et Stykke af et Exemplar ved 

 Bodø paa 60—80 Favne. 



Dübenia elegans kan characteriseres saaledes: 



Rachis robust, rigt besat med Polyper. Finnerne 

 rudimentære, meget korte, bære 5 — 6 lange Polyper. Ved 

 Siden af Finnerne, næsten omfattende deres Basis, 5—6 

 Rader stærkt udviklede Zooider, der som oftest paa Dor- 

 salfladen samle sig i en trekantet Gruppe. Ventralfladen 

 forsynet med en dyb Fure. Farven brunrød eller brun- 

 violet. 



FORKLARING OVER FIGURERNE. 

 Tab. 10, Fig. 1. Dübenia abyssicola, naturlig Størrelse. 

 Fig. 2. Den samme, seet fra Bugsiden, lidt forstørret, a Zooider. 



Fig. 3. Den samme, seet Ira Rygsiden, mere forstørret, a Kalkpla- 

 den og den rudimentære Finne ; b Polyper mere og mindre 

 sammentrukne; c Zooider; d en Polyp, hvor Tentaklerne 

 ere indtrukne og Kroppen noget foldet, antaget Ægformen. 



Fig. 4, En Gruppe Polyper bestaaende af 3, for at vise Sammen- 

 voxningen af Basaldelen mellem den midterste Polyp og 

 Sidepolypernes indvendige Flader, hvorved den rudimen- 

 tære Finne dannes, samt Kalkpladen med dens korte og 

 lange Spieler, stærkt forstørret, a Spieler i Polypens 

 Krop; b Kalkpladen. 



Fig. 5. En Tentakel med Spieler, stærkt forstørret. 



Fig. 6. Kalkspicler i Polypens Krop, stærkt forstørret. 



Fig. 7. Dübenia abyssicola varietas smaragdina, naturlig Størrelse. 

 a 2 sammenloddede Polyper. 



Fig. 8. Den samme, seet fra Bugsiden. 



I nedenstaaende Figurer have samme Bogstaver samme 

 Betydning: 



Fig. 9. Gjennemsnit af Stokken mellem to Grupper Polyper. v 

 Ventralkanal; d Dorsalkanal; s Sidekanal; b Længdekana- 

 ler i Sarcosomaet; V mindre Ernæringskanaler i Axens 

 Skede, som ogsaa væsentligst gaa efter Længden af 

 Stokken. Lignende Kanaler findes ogsaa i Sarcosomaet 

 overalt, hvor dette fortykkes. 



Fig. 10. Gjennemsnit af Stokken lige under Polypernes Udgangs- 

 punkt, rv ventrale Radiærkanaler; rd dorsale Radiær- 

 kanaler; f den rudimentære Finne med talrige capillære 

 Ernæringskanaler. 



polyps of the group; for in these the whole exterior side 

 is free, not connate with the basal part, but merging 

 immediately in the sarcosoma. The polyps can however 

 contract themselves; but as they have no cells, and can- 

 not retire into the sarcosoma, it is merely a simple con 

 traction. This takes place slowly; the long body be- 

 coming successively shorter c and the tentacles invaginated- 

 by which means a polyp thus contracted may assume the 

 most various forms. On account of the sluggishness with 

 which the polyps shrink in, by far the greater number 

 of them appear to be always out, even in spirit speci- 

 mens. The ova are developed in the whole cavity of the 

 body, as well in the perigastric as in the hypogastric 

 spaces, which they may entirely occupy. The axis is rigid 

 round, straight 1 Mm. thick, and above transversely trun- 

 cated. The polypary, together with the polyps, has in 

 the living state a brownish red or brownish violet color. 

 We found it at Molde at the depth of 30—60 fathoms 

 in clayey sand. 



G. O. Sars has found a piece of a specimen at Bodo 

 in 60—80 fathoms. 



Dübenia elegans may be thus characterised : 

 The rachis stout, richly covered with polyps. The 

 fins rudimentary, very short, bearing 5 — 6 long polyps, 

 By the side of the fins, and nearly surrounding their base 

 5—6 rows of strongly developed zooids, which are most 

 frequently collected on the dorsal surface in a three- 

 cornerned group. The ventral surface has a deep furrow. 

 The color brownish red or brownish violet. 

 EXPLANATION OF THE FIGURES, 

 fig. 1. Dühenia abyssicola, natural size. 

 The same viewed from the ventral side, slightly magnified. 

 a zooids. 



The same viewed from the dorsal side more magnified. 

 a the calcareous plate and the rudimentary fin; b polyps 

 more or less contracted; c zooids; d a polyp, in which 

 the tentacles are retracted and the body somewhat folded, 

 having assumed an oval form. 

 Fig. 4. A group of polyps consisting of 3, shewing the connexion 

 of the basal part between the middle polyp and the late- 

 ral polyps' interior surfaces, whereby the rudimentary fin 

 is formed; also the calcareous plate with its short and 

 long spicula strongly magnified, a spicula in the body 

 of the polyp; b the calcareous plate. 



5. A tentacle with spicula strongly magnified. 



6. Calcareous spicula in the body of the polyp, strongly magnified. 



7. Dübenia abyssicola varietas smaragdina, natural size, a 2 

 connate polyps. 



8. The same viewed from the ventral side. 



In the figures below, the same letters have the same 

 signification. 

 Fig. 9. Section of the polypary between two groups of polyps. 

 v the ventral canal; d the dorsal canal; s the lateral 

 canal; b the longitudinal canals in the sarcosoma; V smaller 

 alimentary canals, in the sheath of the axis, which also go 

 chiefly in the longitudinal direction of the polypary. Si- 

 milar canals exist also in the sarcosoma in all those places 

 where it is thickened. 



Section of the polypary inmediately below the point 

 whence the polyps proceed, rv ventral radial canals; 

 rd dorsal radial canals; f the rudimentary fin with nu- 

 merous capillary alimentary canals. 



Tab. 10, 



Fig. 2. 



Fig. 3. 



Fig. 

 Fig. 

 Fig. 



Fig. 



Fig. 10. 



