Syzygialflader, der svare til Reddernes første Led. Som 

 oftest er der to Hovedrødder, som have en forskjellig Længde, 

 fra 20 — 30""". og ere sammensatte af omtrent 20 — 30 Led, 

 Tab. I, Fig. 1 b, 3. Disse have en forskjellig Størrelse 

 og Tykkelse. De øverste ere de tykkeste, deres Længde 

 er dels 0.5""" og Tykkelsen 1.0""", dels kunne de være dob- 

 belt saa lange ; men længere ned paa Roden blive de meget 

 lange, indtil 2.5" 1 " 1 og 1.0""" tykke. De ere runde, lidt 

 smalere paa Midten og udvidede mod begge Ender. Ledde- 

 tladerne ere kompakte, cirkelrunde og have i Midten en 

 liden. rund Aabning, hvorigjennem Fortsættelsen af Cen- 

 tralstrængen løber; de ere lidt ujævne og fast forenede 

 ved en organisk Masse uden nogen Ledbevægelse, Tab. I, 

 Fig. 3k. 



Længere nede paa Roden udspringe fra disse Leds 

 dels midterste, dels øverste Del Grene, som ligeledes beståa 

 af Led, der i Begyndelsen have samme Bygning som Ho- 

 vedrodens, men forandres dog, naar Grenen har antaget 

 en haarformig Finhed. Fra disse Grene udløbe igjen mange 

 yderst fine, indtil haartykke Smaagrene, Tab. I, Fig. 1 c. 

 Disse, saavel som de yderste Ender af Grenene, ere sam- 

 mensatte af meget lange, smale Led. der ere forenede med 

 hinanden ved en elastisk Masse. 



Selve Leddene dannes af tykke, runde lange, noget 

 vredne Kalkbjelker, der ere forenede med korte Tverstokke, 

 hvorved fremkommer et Kalknet med aflange Masker, som 

 ere noget større end Kalkbjelkernes Tykkelse. Baade i 

 Grenene og i Smaagrenene er der en Kanal i Midten, li vis 

 Vægge ere tapetserede med en Membran, hvori sees aflange 

 Celler med Kjerne og et gult, kornet Indhold. Ogsaa paa 

 den ydre Flade ere Grenene saavel som Hovedrødderne 

 forsynede med en tynd, gjennemsigtig Membran, der sand- 

 synligvis er en Fortsættelse af den, som beklæder den 

 hele Stilk. 



Hovedet (Kronen) er paa det største Exemplar 30""" 

 langt; det er sammensat af 5 Grundled (Basalia) og 3 

 Rækker Straaleled (Radialia), 5 i hver Række. Den tredie 

 Rækkes Straaleled ere tillige Axillarier og bære 10 Arme, 

 forsynede med Pinnuler. Indenfor Radialerne er Krops- 

 hulheden, dækket af Perisomet. 



Basalerne ere meget smaa, fem kantede, med fuldstæn- 

 digt sammenvoxede Siderande, saa at de danne en rund. 

 glat Ring, som er meget udvidet foroven, Tab. I, Fig. 3 1. 

 Paa meget unge Individer kan med meget stærk Loupe sees 

 5 yderst fine Somme, Tab. I, Fig. 2 h, der vise paa det 

 Bestemteste, at de have været adskilte, men som ganske 

 forsvinde hos ældre Dyr. Den øverste Basalrand er paa 

 Midten afrundet og skraaner lidt af til Siderne mod de 

 tilstødende Basaler, hvorved Leddefladerne for de første 

 Radialer fremkomme. Den inderste Rand er afstumpet 

 og støder til den cirkelrunde Centralkanal. Basalernes 

 øverste Rand danner en Pentagonal, Tab. I, Fig. 3 m, 7. i 

 hvis Indskjæringer Leddefladene tindes for de Iste Radia- 



depressed syzygial surfaces, which correspond to the first 

 joint of the roots. Most frequently there are two chief 

 roots, with a different length, from 20 — 30""", and composed 

 of about 20 — 30 joints (Pl. I, figs. 1 b, 3). These have a 

 variable size and thickness. The uppermost ones are the 

 thickest, their length is partly 0.5""" and the thickness 

 1.0""", partly they may be twice as long; but farther down 

 on the root they become very long, up to 2.5""", and 1.0""" 

 in thickness. They are round, a little narrower in the 

 middle and expanded towards both extremities. The ar- 

 ticular surfaces are compact, circular, and in the middle 

 have a small round aperture through which the continuation 

 of the central cord runs ; they are somewhat uneven, and 

 are firmly united by an organic substance without any arti- 

 cular flexibility (Pl. I, fig. 3 k). 



Farther down the root there issue, partly from the 

 medial partly from the uppermost part of these joints, 

 branches, also composed of joints which at the commence- 

 ment have the same structure as those of the main root, 

 but become changed, however, when the branch has as- 

 sumed a capilliform fineness. From those branches there 

 again issue many extremely delicate — some not thicker than 

 a hair — , small branches ( Pl. I. fig. 1 c). These, as well 

 as the outermost extremities of the branches are composed 

 of very long, narrow joints, which are united to each other 

 by an elastic mass. 



The joints themselves are formed of thick, round, 

 long, somewhat twisted calcareous beams which are united 

 by short transversal rods, thereby causiug the production 

 of a calcareous reticulation witli oblong meshes which are 

 somewhat larger than the thickness of the calcai-eous beams. 

 Both in the branches and in the small sub-branches there 

 is a canal in the middle. whose walls are lined with a 

 membrane in which are seen oblong cells with nucleus and 

 a yellow granular substance. Also on the outer surface 

 the branches as well as the main roots are furnished with 

 a thin, transparent membrane. which is probably a con- 

 tinuation of that which clotbes the entire stalk. 



The head (the crown) is, in the largest specimens, 

 30""" in length; it is composed of 5 main joints (Basalia) 

 and 3 series of radiate joints (Radialia), 5 in each series. 

 The third series of the radial joints are also axillaria, and 

 carry 10 arms furnished with pinnules. Inside of the radials 

 the body-cavity is covered by the perisome. 



The basals are very small, pentagonal, with comple- 

 tely concreted lateral margins, so that they form a round, 

 smooth ring which is somewdiat expanded at the top (Pl. 

 I, fig. 3 1). In very young individuals there may be seen, 

 with the aid of a very powerful magnifier, 5 extremely fine 

 seams (Pl. I, fig. 2 h) - - showing in the most conclusive 

 manner that they have been separated, — but which cpiite 

 disappear in " the older animals. The uppermost basal 

 margin is rounded in the middle, and slopes off a little to 

 the sides towards the adjacent basalia, producing thereby 

 the articular surfaces for the first radials. The innermost 

 margin is obtuse and unites to the circular central canal. 

 The uppermost margin of the basalia forms a pentagon 



