65 



Drifa islandica, n. sp. 



Tab. VI, Fig. 30—71. 



Zoanthodemet indtil 60""" liøit. Stammen, der ved 

 Grunden er 45""" i Omkreds, er rund, riflet efterLængden 

 af de stærkt udprægede Længdekanaler og ender opad i 

 3 Grene. Basaldelen er fast, læderagtig og skiveformigt 

 udvidet. Lige fra Basaldelen og til Toppen er Stammen 

 rundtom rigt forsynet med Grene, der kun ved nogle 

 Millimeters Mellemrum ere skilte fra hverandre. Grenene 

 have forskjellig Længde og opnaa indtil Halvdelen af 

 Stammens Tykkelse, ere runde med udprægede Længde- 

 kanaler og i Regelen lige fra deres Udspring tæt besatte 

 dels med Smaagrene, dels med enkelte Polyper. Smaa- 

 grenene ere korte, tykke, fra 4 — 6""" lange og bære overalt 

 Polyper, som ere ordnede i tætte Grupper. Enkelte 

 Smaagrene, men disse ere sjeldne, ere ved Grunden om- 

 givne af enkeltsiddende Polyper og bære paa Enden en 

 hel Samling af saadanne. Smaagrenene ligne paa Grund 

 af den Masse Polyper, de bære, Drueklaser og dække som 

 oftest ganske Hovedgrenen. Saavel Grenene som Smaa- 

 grenene ere bløde, bøielige og forsynede med Spikier, der 

 vanskelig sees med blotte Øie, men meget let ved en 

 svag Loupeforstørrelse ; de vise sig da som smaa, lysende 

 Kommaer, der ligge temmelig langt fra hverandre. Paa 

 Stammen, som er fastere end Grenene, sees overalt imellem 

 disse dels enkelte Polyper, dels Grupper, der ere samlede 

 i en liden Stilk, som gaar direkte over i Stammen. Ogsaa 

 paa denne iagttages mere eller mindre spredte Spilder, 

 som tildels ere ordnede i Længderækker, der følge Længde- 

 kanalerne, men ligesaa hyppigt samle sig i smaa Klumper, 

 som kunne sees med blotte Øie, Fig. 30. 31. 



Polyperne ere traktformige, 8 — 9'"™ lange. For- 

 kroppen med Tentakelranden stærkt udvidet, 3 — 4""" bred. 

 Bagkroppen forholdsvis smal, 3"'"' lang, Fig. 32. Hele 

 Kroppen er stærkt inkrusteret af Spikier, naar uncltages 

 op imod Tentakelranden, hvor der imellem Tentaklerne er 

 et triangulært Spatium, som er blottet for Kalk, Fig. 33, a. 

 Paa Kroppens forreste Del op imod Tentaklerne ordne 

 Spiklerne sig i Længderækker og danne Kibber, der gaa over 

 paa Tentaklernes aborale Side lige til deres Ende, Fig. 

 32. 33. Paa Kroppens Bugside ligge Spiklerne ikke saa 

 tæt sammen som paa den øvrige Del af Kroppen 1 . Ten- 

 taklerne ere omtrent S mm lange med korte, tykke Pinnuler, 

 der ere uden Spilder. Mundskiven er lidt hvælvet, og i 

 dens Midte sees den aflange Mund, fra hvis Læber udløbe 



1 Dette er forresten Tilfældet med de fleste Polyper hos de 

 Slægter, jeg har undersøgt. Hyppigt er der endogsaa et større eller 

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



Drifa islandica, n. sp. 



Pl. VI, figs. 30—71. 



The Zoanthodem measures up to 60'"'" in height. 

 The stem, which at the base measures 45 mm in circum- 

 ference, is cylindrical, longitudinally grooved by the strongly 

 prominent longitudinal ducts, and terminates, above, in 3 

 branches. The basal part is firm, coriaceous, and cliscoid- 

 ally dilated. Quite from the basal part and up to the 

 summit, the stem is, round about it, furnished with bran- 

 ches, which are only separated from each other by a 

 space of a few millimetres. The branches are of variable 

 lengths, and attain a thickness of up to half that of 

 the stem; they are cylindrical, have prominent longitud- 

 inal ducts and, as a rule, are, quite from their root, 

 closely beset with, partly, branchlets, partly with single 

 polyps. The branchlets are short and thick, measuring from 

 4—6™'" in length, and everywhere carry polyps arranged 

 in close-set groups. A few of the branchlets, but they are 

 rare, are, at the root, encompassed by isolately situated 

 polyps, but on the extremity carry a whole collection of 

 them. The branchlets resemble, by reason of the mass of 

 polyps that they carry, clusters of grapes, and, most fre- 

 quently, quite cover the main branch. Both, the branches 

 and the branchlets, are soft and flexible, and are furnished 

 with spicules that can with difficulty be observed with the 

 naked eye but are quite easily observed on slight magnifica- 

 tion; they appear then, as minute, glancing commas, 

 placed pretty far apart from each other. On the stem, 

 which is firmer than the branches, there is seen between 

 these, everywhere, partly single polyps, partly groups 

 which are collected into a small stalk that is produced 

 direct into the stem. More or less dispersed spicules 

 can also be observed on it, which, partly, are arranged 

 in longitudinal series that follow the longitudinal ducts, 

 but quite as frequently, they collect themselves into small 

 clumps which may be observed with the naked eye (figs. 

 30. 31). 



The polyps are infundibuliform, and measure, 8 — 9'"'" in 

 length. The anterior body, towards the tentacular margin, 

 is strongly dilated, and measures 3—4""" in breadth. The 

 posterior body is relatively narrow, and measures 3'"'" in 

 length (fig. 32). The entire body is strongly encrusted 

 with spicules, with exception of the part up towards the 

 tentacular margin, where, between the tentacles, there is 

 a triangular space devoid of calcium (fig. 33, a). On the 

 anterior part of the body, up towards the tentacles, 

 the spicules arrange themselves in longitudinal series and 

 form ribs which are produced to the aboral side of the 

 tentacles, right to their extremity (figs. 32. 33). On the 

 ventral side of the body, the spicules are not situated so 

 closely together as on the rest of the bodv 1 ). The ten- 



1 This is also the case with most of the polyps in the genera 

 which I have observed. Most frequently, there is, even, a larger 



9 



