95 



sterile Del er stærkt contractu, og ofte antager den ne- 

 derste Ende en Blæreform. Den polypbærende Stilk er 

 2.7a Gang saa lang, som den polypløse. Polyperne ere 

 3 — 4 Mm. lange, cylindriske, småle, ved deres Basaldel 

 sammenvoxede, saa at derved opstaar en Slags Finne, 

 der kan betragtes som rudimentær (Tab. 10, Fig. 3 a), 

 ikke over 0,5 Mm, høi og danner paa Sarcosomaet kun 

 en ringe Fremstaaenhed, hvorfra Polyperne, der ialmin- 

 delighed ere 3, sjelden 4 i Antal, udspringe. Paa Grund 

 af Finnens ringe Høide ser det ud, som om Polypen 

 springer ud fra selve Sarcosomaet, og naar den er sam- 

 mentrukken, hvilket sker paa den Maade, at først træk- 

 ker den nederste Del af Kroppen sig sammen, og deref- 

 ter indkrænges Tentaklerne, saa ser man en liden Knop 

 paa Stokken, hvilken kan antage en forskjellig Form, 

 stundom næsten Kugleformen, stundom Ægformen (Tab. 10, 

 Fig. 3 d). Naar Polypen saaledes er sammentrukken, ra- 

 ger Kalkpladens længere Spieler langt over den. Polyperne 

 staa vidt fra hverandre, have temmelig lange Tentakler, 

 der paa deres aborale Flade ere forsynede med Spicier, 

 som gaa lige til Tentakelspidsen og strække sig lidt ned 

 paa Kroppen (Tab. 10, Fig. 4, 5). Denne har desforuden 

 1 stundom 2 Rækker Spieler (nemlig 1 paa hver Side), 

 hvilke sjelden indtage Kroppens hele Længde. Disse 

 Spieler ere meget robustere, kortere og mere afstumpede 

 end cle, der findes paa Tentaklerne (Tab. 10, Fig. 4 a 

 og Fig. 6). Finnerne sidde afvexlende, dog saaledes, at 

 medens de paa Midten og den nederste Del af Rachis 

 næsten sidde hinanden modsat, ere de meget afvexlende 

 paa dennes øverste Del. De ere som oftest conver- 

 gerende mod Dorsalfladen, hvor de støde næsten til hinan- 

 den, men vige fra hinanden paa Bugfladen, saa at denne 

 er blottet i en smal Stribe. 



De rudimentære Finner støttes af en Kalkplade, der 

 er sammensat af korte og lange Spieler, og som tager 

 sin Begyndelse med en Spids fra Stokken, strax under 

 Finnen, indtager dennes Bredde og rager med sine lange 

 Spieler, hvoraf der hyppigst ere 9, frit op dels imel- 

 lem Polyperne, dels paa deres Krop. Paa Midten af 

 Stokken sidde Finnerne temmelig langt fra hverandre 

 indtil 5 Mm. 's Afstand, længere nede blive Mellemrum- 

 mene mindre, indtil de næsten ganske forsvinde der, hvor 

 de unge Polyper begynde. Imod den nederste Ende af 

 Rachis aftage Finnerne betydeligt i Størrelse, danne 

 Tverrader med 3 Polyper, saa komme 2 Polyper og en- 

 delig blot 1 Polyp. Nedenfor denne sees en lang Stribe 

 af Zooider (Lateralzooidstriben). 



Paa de ældre Individer findes over Finnerne en Sam- 

 ling Zooider, der udgaa fra hver Side af Stokken, hvor de 

 danne en smal ophøiet Liste, og støde sammen i en større 

 eller mindre Gruppe paa Dorsalfladen (Tab. 10, Fig. 3 c). 

 Disse Zooider kunne dog være meget sparsomme ved enkelte 

 Finner, ligesom Tilfældet altid er paa yngre Exemplarer, 

 hvor de kun staa enkeltvis og ere saa smaa, at de endog 

 vanakeligen kunne sees ved Hjælp af en stærk Loupe. 

 Saavel paa Dorsal- som Ventralfladen af Rachis sees i Nær- 

 heden af Finnerne en svag Vulst, der har en forskjellig 



the lower part of it often assumes the form of a bladder. 

 The polypiferous stalk is 2 i / 2i times as long as the ste- 

 rile part. The polyps are 3 — 4 Mm. long, cylindrical, 

 narrow and connate at their basal part so as to form 

 a sort of fin which may be considered as rudimentary 

 (Tab. 10, fig. 3 a) not more than 0,5 Mm. high and 

 causing only a slight protuberance on the sarcosoma from 

 which the polyps, usually 3, rarely 4 in number, issue. 

 On account of the inconsiderable height of the fin, the 

 polyps appear to proceed from the sarcosoma itself; and 

 when it is contracted, which takes place by the lower 

 part of the body being first drawn together, and then 

 the tentacles invaginated, a small knob appears on the 

 polypary and may assume different forms, being some- 

 times nearly globular and sometimes oval (Tab. 10, fig. 3 d). 

 When the polyp is thus contracted, the longer spicula of 

 the calcareous plate project far beyond it. The polyps are 

 situated far apart from each other; they have rather long 

 tentacles, which on their ab oral surface have spicula reach- 

 ing right up to the point of the tentacles and extending 

 a little way down on to the body (Tab. 10, fig. 4, 5). The 

 body has besides, 1, sometimes 2 rows of spicula (namely 

 1 on each side) which seldom occupy the whole length of 

 the body. These spicula are much stouter, shorter and 

 terminate more obtusely than those which are found in 

 the tentacles (Tab. 10, fig. 4 a and fig. 6). The fins are 

 situated alternately, but so that, while in the middle and 

 lower part of the rachis they are nearly opposite to each 

 other, they are quite alternate in the upper part. They 

 are usually convergent towards the dorsal surface, where 

 they nearly touch, but diverge towards the ventral surface, 

 so that a narrow band of this surface is bare. 



The rudimentary fins are supported by a calcareous 

 plate, composed of short and long spicula, beginning in 

 a point from the polypary just below the fin, occupying 

 the whole breadth of the fin, and projecting with its long 

 spicula, of which there are usually 9, freely upwards, 

 partly between the polyps and partly on their body. In 

 the middle of the polypary the fins are situated rather 

 far from each other, as far as 5 Mm. apart; lower down 

 the intervals are smaller, until they nearly disappear where 

 the young polyps begin. Towards the lower end of the 

 rachis the fins diminish considerably in size and form trans- 

 verse rows with 3 polyps; then come 2 polyps and finally 

 only 1 polyp. Below there appears a long band of zooids 

 (the lateral zooid-band). 



In elder specimens there is above the fins a collec- 

 tion of zooids proceeding from each side of the polypary, 

 where they form a small raised border and meet in a larger 

 or smaller group on the dorsal surface (Tab. 10, fig, 3 c). 

 These zooids may yet be very scarce on some fins, as is the 

 case always in younger specimens, where they only stand 

 singly and are so small that they are not easily visible, 

 even with the help of a strong magnifying glass. As well 

 on the dorsal, as on the ventral surface of the rachis, 

 there appears, in the vicinity of the fins, a slight swelling 



