Legemet er femarmet. Det største Exemplars Gjen- 
nemsnit er 247”; Hoiden 6””. Forholdet imellem den lille 
og store Radius som 1:4. Ryggen meget hvælvet, over- 
alt besat med Paxiller, der staa omtrent 0.57” fra hver- 
andre, Fig. 1. Analaabningen subcentral, omgiven af 5 
Paxiller. Madreporpladen er lidt hvælvet, aflang og sid- 
der ganske i Nærheden af Anus. 
Armene ere ved deres Grunddel meget smale, kun 
5”, men blive efterhaanden bredere i en Udstrækning af 
3—4””, hvor de opnaa den største Bredde, nemlig 8—9””; 
den øvrige Del af Armene, der smalner af mod Spidsen, 
er 10”” lang, Fig. 3. Enhver Arms Rand danner paa sin 
indre Del en Vinkel, Fig. 3, a, saaledes at Hjørnet af denne 
paa den ene Arm nærmer sig stærkt til den anden Arms 
tilstødende Vinkelhjørne, Fig. 3. 4, saa at en Spalte op- 
staar imellem Armenes Grunddel, Fig. 3, b, hvilken fort- 
setter sig i en temmelig dyb Fure paa Rygfladen, Fig. 3, c. 
Paa Rygskiven ere Paxillerne stillede næsten kreds- 
formig; paa Armene derimod staa de i regelmæssige 
Rækker, Fig. 5, der gaa fra Armens ene Rand til den 
Enhver Paxille bestaar af en Samling af 6—10 
meget lange, yderst spidse Kalknaale, Fig. 5,a.6, som paa 
anden. 
sin nederste Del ere halvt omgivne af en Kalkskede, der 
har en udvidet, halvrund, gjennembrudt Grunddel, Fig. 7, a, 
som, idet den støder noie til den tilsvarende Kalkskedes 
Grunddel, danner Paxillens Basaldel, der har en rund!Ar- 
ticulationsflade, Fig. 6, a. Kalkskedernes Grunddele 
stillede i en Kreds, Fig. 6, a, og ere sammenbundne med 
ere 
en stærk Bindevævsmembran, der beklædes af Huden, som 
forlænger sig op over samtlige Kalkskeder, der udgjør om- 
trent 1.5”” i Længde, imedens Kalknaalen, som Skeden 
omfatter, er 4—5”” Jang paa Skiven og Ryggen af Ar- 
mene, men kun omtrent 3”” paa Armenes Sider. Ved 
denne Forlængelse af Huden opover Skederne bindes Naa- 
lene end stærkere sammen og erholde Formen af et Bæ- 
ger. Hver Paxille er forsynet med stærke Muskelfibre, 
der udbrede sig opover Basaldelen. 
Paxillerne artikulere med den lille, knopformige Led- 
flade, fimdes paa Ryggens Kalkplader, Fig. 3, d. 
Disse ere store, flade, skjælformige, omtrent ligesaa lange 
som brede, med noget afrundede Rande; paa Midten ere 
de kompakte og have paa deres ydre, noget ophøiede Flade 
den føromtalte runde, knopformige Articulationsflade, — 
imedens Pladernes Sidedele ere tynde, tildels gjennemsig- 
der 
tige, saa at det netformige 1 Bygningen kan iagttages, Fig. 
14. Enhver Plade bærer Paxille.  Kalkpladerne paa 
Siderne af Armene ere mere langstrakte, næsten ovale, 
Fig. 3, e. Samtlige Kalkplader ere tæt taglagte, danne 
regelmæssige Rækker, Fig. 3, der fulkommen svare til de 
en 
96 
The body is 5-rayed. The diameter of the largest 
specimen is 24”, and its thickness is 6””. The disk rad- 
ius bears to the brachial radius. the proportion of. as 1:4. 
The abactinal surface is much arched, and is, everywhere, 
beset with paxillæ, placed about 0.57” apart from each 
other (fig. 1). The anal aperture is subcentral, and sur- 
rounded by 5 paxillæ. The madreporite is oblong, and 
slightly convex, and is situated in immediate proximity to 
the anus. 
The rays are very narrow at their origin, being only, 
here, about 5”” broad, but they become, gradually, broader, 
through an extent of 3—4”” of the brachial length, and 
then attain their maximum breadth of 8—9”". The re- 
maining part of the rays tapers off towards the tip, 
and this part is 10" long (fig. 3). The margin of 
each ray, forms at the inner part, an angle (fig. 3, a), in 
such manner, that the apex of the angle of one ray, 
approaches nearly, to the apex of the corresponding angle 
of the adjoining ray (figs. 3. 4) forming a fissure, thus, 
between the origins of the trays (fig. 3,0), which becomes 
continued into a rather deep furrow on the abactinal sur- 
face (fig. 3, ¢). 
On the abactinal disk, the paxille are arranged in 
nearly ring-form, but upon the rays, they are, on the other 
hand, arranged in regular series (fig. 5), extending from one 
margin of the ray to the other margin. Each paxilla con- 
sists, of a collection of 6—10 very long, extremely acumi- 
nate calcareous needles (fig. 5, da. 6) which, upon the lower 
part. are half encased by a calcareous sheath, with a dil- 
ated semicircular perforated basal part (fig. 7, a). By 
butting immediately to the corresponding calcareous sheath’s 
basal part, it forms the paxillas basal part, which also, 
is furnished with a circular articulatory surface (fig. 6, a). 
The basal parts of the caleareous sheaths, are arranged in 
a ring (fig. 6, a) and, are united together by a strong 
connective-tissue membrane, which again, is covered by the 
integument that extends over all the calcareous sheaths. 
These are about 1.5”" in length, whilst, the calcareous 
needles, which the sheaths encase, are 4.5”” in length on 
the disk and the abactinal surface of the rays; but only 
about 5”” in length, on the lateral surface of the rays. 
By the extension of the integument over the sheaths, the 
needles are still firmer bound together, and they acquire 
the form of a chalice. Each paxilla is furnished with 
strong muscular fibres, which spread up, and around its 
basal part. The paxillæ articulate with the small knob- 
formed articulatory surfaces found on the calcareous plates 
of the abactinal surface (fig. 3, d). These are large, flat, 
and scale-formed, and are about as broad as they are long, 
In the middle, 
they are compact, and carry, on their outer, somewhat 
raised surface, the previously spoken of, round, knob-formed 
articulatory surfaces. The lateral surfaces of the plates 
are thin, and semi-transparent, so that the reticulated con- 
struction can be observed (fig. 14). 
paxilla. 
whilst the margin is somewhat rounded. 
Each plate carries a 
The calcareous plates on the lateral surfaces of 
the rays, are more elongated, and nearly oval (fig. 3, e). 
