119 



lindes lidet Coenenchym, der dog har Spikier. Stammen, 

 Grenene og deres Coenenchym rigt paa Spikier. Svælget 

 forsynet med Spikier. 



Artsk ar akter. 



Zoanthodemet indtil 25'"™ høit. Basaldelen membran- 

 agtigt udvidet. Stammen fast, furet, nøgen i større Stræk- 

 ninger. Grenene y der st faa, 3 — 4, korte, endende i en 

 tyk Klump, rigt besa-t med Polyper. Disse ere langstrakte, 

 cylindriske, staa tæt sammen og forsynede med 8 Længde- 

 ribber, i meil em hvilke 8 nedsænkede Felter. Tentaklerne, 

 omtrent halvt saa lange som Kroppen, have Spikelbeklæd- 

 ning paa hele deres aborale Made. Pinnulerne spikelholdige. 

 Polypcellen halvrund, otteribbet og spikelrig, Svælget har 

 4 Dobbeltrækker Spilder. Paa Basaldelen almincleligst ellip- 

 tiske, takkede Spindler, Dobbeltstjerner og Druespikler. 

 Paa Stammen hyppigst sammensatte Stjerner, Dobbelt- 

 stjerner, Spindler og Druespikler. Paa Grenene takkede 

 Køller. Paa Polypkroppen lige og krummede, takkede 

 Spindler og takkede Valser. Svælg- og Coenenchymspiklerne 

 væsentlig takkede Spindler. 



Nidalia arctica, n. sp. 



Tab. XXI, Fig. 29—136. Tab. XXII, Fig. 07—83. 



Zoanthodemet indtil 35 mrtl høit. Basaldelen membra- 

 nøs, rørformigt udvidet, dannende en større eller mindre 

 Hulhed, udfyldt med en mørk Lermasse, Fig. 29, a. 

 Stammen, omtrent 25""" høi og Q mm bred ved Overgangen fra 

 fra Basaldelen, er i en Strækning af 10"™ nøgen, rund, 

 lidt furet paalangs, Fig. 29. b. men udvider sig nu til en 

 Bredde af i0 mm , Fig. 29, c, imedens den mod Toppen 

 smalner lidt af. Det er denne udvidede Del af Stammen, 

 der bærer Polyperne, og som. naar disse ere lidt sammen- 

 faldne, antage Formen af en Strobilus. 



Polypcellerne staa tæt sammen, ere temmelig vide, 

 runde, med 8 stærke Bibber, der aftage noget i Styrke, 

 idet de gaa over paa Polypens Bagkrop og ere adskilte ved 

 ligesaa mange spikelløse Furer, Fig. 30, t. 



between them, little sarcosoma can be observed ; it, however, 

 contains spicules. The stem, the branches and their sarco- 

 soma, rich in spicules. The gullet furnished with spicules. 



Specific characteristics. 



The Zoanthodem measures up to 25'"'" in height. The 

 basal part is membranaceously dilated. The stem hard, 

 grooved, and bare over a considerable extent. The branches 

 extremely few in number (3 — 4 short ones), terminate in a 

 thick clump richly beset with polyps. These are elongato- 

 cylindrical, placed closely together, and are furnished with 

 8 longitudinal ribs, between which there are 8 depressed 

 areas. The tentacles about half the length of the body, and 

 furnished with a spicular sheathing on their aboral surface. 

 The pinnules contain spicules. The polyp-cell semi-circular, 

 eight-ribbed, and contains spicules abundantly. The gullet 

 has four double series of spicules. In the basal part, elliptic, 

 spicate fusees, bistellates, and racemiform spicules are the 

 most frequent. In the stem, complex stellates, bistellates, 

 fusees, and racemate spicules are, most usually, observed. 

 On the branches, spicate subclavates. On the polyp-body, 

 straight, and curved, spicate fusees, and spicate cylinders. 

 ■ The gullet and sarcosoma spicules are principally spicate 

 fusees. 



Nidaiia arctica, n. sp. 



PL XXI, figs. 29—66. PL XXII, figs. 67—83. 



The Zoanthodem measures up to 35" m in height 

 The basal part is membranaceous, tubularly dilated, and 

 forms a larger or smaller cavity filled with a dark- 

 coloured aluminous substance (PI. XXI, fig. 29, a). The 

 stem measures about 25 mm in height, and 6 mm in breadth at 

 the transition from the basal part. Through an extent of 

 10""" the stem is bare; it is cylindrical, slightly grooved 

 longitudinally (PI. XXI, fig. 29, &), bnt then becomes dilated 

 to a breadth of 10'""' (PI. XXI, fig. 29, c), whilst, towards 

 the summit it diminishes in thickness a little. It is upon 

 this dilated part of the stem that the polyps occur,' and 

 when the polyps are a little retracted they acquire the 

 form of a Strobil. 



The polyp-cells are placed closely together, and are 

 pretty wide; they are cylindrical, and have 8 strong ribs 

 which diminish in strength, somewhat, as they pass over 

 to the posterior body of the polyp, and they are separated 

 from each other by an equal number of spicule-free grooves 

 (PL XXI, fig. 30, &.) 



