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26
for de dorsale, og hver enkelt Pigs Skede bærer paa sin
ydre Flades øverste Del, ligeved Randen, en korsformet
Pedicellarie, Fig. 3, /. 5, a, der rager saa langt ud, at
den godt kan sees fra Rygsiden; kun paa en Skede saaes
to Pedicellarier.
De korsformede Pedicellarier have en bred Stilk. De
ere meget smaa, men omgivne af en temmelig vid
Membran, Fig. 3, /. Basaldelen frembyder intet Særegent.
Kjæverne ere langs hele Midten af den ydre Flade
forsynede med Alveoler, Fig. 6, a, og deres bredeste, nederste
Del er temmelig spidsvinklet, Fig. 6, b. Randene, ligesom
den indre Flade, ere tæt besatte med stærke Tænder. Den
forlængede Del har paa sin fri, afstumpede Elides ydre
Flade en liden Gruppe Takker, Fig. 6, c.
Bugen er flad. Anibulacralfuren, der er temmelig bred,
har 4 Rækker cylindriske Fødder uden Spikier; dens Rande
ere paa Armens indre Del forsynede med 2 Rækker Pigge,
Fig. 7; derimod paa Midten er der afvexlende 2 og 1,
Fig. 5, b, og paa den ydre Trediedel af de fleste Anne er
der kun 1 Række Ambulacralpigge, Fig. 7, c.
Langs Ambulacralfuren, paa Randens indre Væg, sees
meget smaa, ligeformede, kortstilkede Pedicellarier, der dels
staa enkeltvis, dels 2—3 sammen. Deres Basaldel er
trekantet, Fig. 8, a, med en næsten tvers afskaaren øverste
Rand. Kjæverne ere langstrakte med en noget til Siderne
hvælvet Overflade; Randene og den indre Flade fint
sag-takkede, Fig. 8.
Mundpladerne ere temmelig lange og smale, have paa
Midten 2 lange, stærke Tænder, Fig. 7, b, og paa hver
Siderand 4 lange Pigge, Fig- 7, a, der hver bærer paa
Spidsen en korsformet Pedicellarie. Paa Mundpladernes
Underflade enkelte smaa Pigge, Fig. 7.
Ryggens Hudskelet bestaar af et meget vidmasket
Kalknet. Det dannes af smaa, smale, aflange Kalkstykker, der
taglagt lægge sig paa hverandre, hvorved fremkommer lange
Kalkbjelker, Fig. 9, a; og der, hvor Maskerne bindes
sammen, er et større, mere eller mindre rundt Kalkstykke, som
bærer en af de førbeskrevne Pigge, Fig. 9, b. Langs
Midten af Armens ydre Trediedel ordne Kalkstykkerne sig i
en regelmæssig Række, Fig. 9, c, der strækker sig ned til
den forholdsvis store Ocularplade, Fig. 9, d.
Randpladerne ere langstrakte, ovale og have paa sin
ydre, hvælvede Flade en Leddeflade for Randpiggpn, Fig. 9, e.
Farven er gulrød paa Ryggen, hvor Piggene med
situated directly opposite to the dorso-marginal spines. The
sheath of each individual spine, carries, on its superior,
exterior surface, close to the margin, a cruciform pedicellaria
(fig. 3,/, 5, a), which projects so much, that it is easily visible
from the abactinal side. Upon only one sheath did we
find two pedicellariæ.
The cruciform pedicellaria have a broad peduncle;
they are very small, p,nd are surrounded by a rather wide
membrane (fig. 3, /). The basal portion presents nothing
noteworthy. Along the entire mesial surface, the jaws are
furnished with alveoli (fig. 6, a), and their broadest,
inferior portion, forms a rather acute angle (fig. 6, b). The
margins, as, also, the interior surface are closely beset with
strong teeth. The elongate portion has a small group of
spikes, situated, on the exterior surface of its blunted free
extremity (fig. 6, c).
The actinal surface is flat. The ambulacral furrow
is rather broad, and is furnished with four series of
cylindrical suckers devoid of spiculæ; the margin on the diskal
part of the rays, is furnished with two series of spines,
(fig. 7), whilst on the mesial part of the rays, the spines
occur, 2, and 1, alternately (fig. 5, b), and upon the distal
third part of most rays, there is only one series of
ambulacral spines (fig. 7, c).
Along the ambulacral furrow, on its internal marginal
wall, very small, rectiform, short pedunculated, pedicellariæ
are seen, placed, partly, singly, and partly, 2—3 together.
The basal portion is trilateral in form (fig. 8, a), with a
nearly truly-truncate superior margin. The jaws are
elongate, and have a somewhat laterally placed, rounded,
superior surface. Their margins and internal surface are
minutely serrated (fig. 8).
The oral plates are rather long, and narrow, and in
their mesial part, are furnished with 2 long strong teeth
(fig. 7, b), and on each lateral margin, with 4 long spines
(fig. 7, a), all of which, carry a cruciform pedicellaria on
the pointed extremity. On the inferior surface of the oral
plates, a few small spines occur (fig. 7).
The abactinal dermal skeleton consists, of a very wide
meshed calcarous reticulation, formed, of small, narrow,
oblong, calcareous ossicles, which lie imbricate upon each
other, producing thus, long calcareous rods (fig. 9, a).
At the point where the meshes become connected together,
there is found, a largish, more or less round,
calcareous piece, carrying one of the spines previously described
(fig. 9, b). Along the mesial line of the distal third of
the ray, the calcareous ossicles arrange themselves in
regular series (fig. 9, c), extending down to the
proportionally large ocular plate (fig. 9, d).
The marginal plates are elongate, ovate, and upon
their exterior convex surface, have an articulatory surface
for the marginal spine (fig. 9, e).
The colour is orange on the abactinal surface, where
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