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61
vor, og ved Hr. Professor Sven Lovéns Forekommenhed
fik vi udlaant fra Stockholms Museum to af
Originalexem-plarerne, hvorved vi overbeviste os om, at vi havde med den
samme Søstjerne at gjøre.
Vi kunne ikke, som Hr. Stuxberg, henføre den til
Slægten Solaster, fra hvilken den i høi Grad adskiller sig
ved Hudskelettets Form, ved Interbrachialsystemet og ved
Odontophoren.
Nødvendigvis tilhører den den store Familie Asterinidæ
og nærmer sig da temmelig stærkt til Asterina, til hvilken
vi ville henføre den, ihvorvel den adskiller sig noget fra
denne ved Hudskelettet, der paa Rygfladen ikke frembyder
den særegne Anordning af Kalkpladerne, ved den store
Mængde Tentakelporer, der ere udbredte over hele
Rygfladen lige til Randen, saavel paa Armene som paa
Skiven, samt ved de skjulte Randplader og deres Fonn.
Legemet er stærkt konvex paa Ryggen, fladt paa
Bugen, har 5 korte, tykke Arme, Tab. XV, Fig. 2. Den
lille Radius forholder sig til den store som 5—8.
Ryggens Overflade er beklædt med’ tætstaaende
Pax-iller, der næsten have Bægerformen, bredere foroven,
smalere forneden, og dannes af en gjennembrudt Kalksøile,
paa hvis øverste^ frie Ende rager op en Mængde
Kalkspidser, der paa den ydre Rand staar næsten i en Krands, og
imellem hvilke Spidser sees en yderst tynd, vandklar
Membran, der overtrækker hele Paxillen, Tab. XI, Fig. 8.
Imellem Paxillerne iagttages mangfoldige Tentakelporer,
der ere udbredte over hele Rygfladen lige til Randen af
Armene og Interbrachialrummet.
Analaabningen subcentral. Madreporpladen, der paa
smaa Exemplarer er rund, paa det største Exemplar lidt
aflang, er stillet omtrent midt imellem Anus og
Søstjernens afrundede Rand.
Ambulacralfuren er paa Midten bred, smal mod begge
Ender og forsynet med 2 Rader spikelløse Fødder med
Sugeskive, Tab. X, Fig. 1. Langs Furens Rand er 3
Rækker Pigge, 2 i hver Række, af hvilke de 2 inderste,
Tab. X, Fig. 1, b, ere de længste og tjene til at dække
Furen, idet de møde de tilsvarende 2 fra den modsatte
Rand.
Interbrachialrummene ere trekantede, meget brede
udad mod Randen, Tab. X, Fig. 2. De ere tæt besatte
med særegne Paxiller, der ere langstrakte med 6—8
Takker. Hele Paxillen er omgiven af Cuticula og Epithelet,
kun Takkerne ere blottede, Tab. XI, Fig. 7.
Randpladerne ere næsten skjulte af den tykke
Hudbeklædning og kunne først ret sees, naar enten Dyret er
aabnet fra Ryggen, Huden slaaet tilside og en svag kaus-
ably, his specimen was a young one of ours. Through the
kindness of Prof. Sven Lovén, we obtained from
Stockholm Museum the loan of two of the original specimens,
and Were able to satisfy ourselves, that it was the same
starfish with which we had to do.
We are unable, however, to assign it to the genus
Solaster, as Dr. Stuxberg has done, because, it differs in
a marked degx-ee, in the form of the dermal skeleton, the
interbrachial system, and the odontophore.
It of necessity, belongs to the large family of
Asterinidæ, and approaches pretty much to Asterina, to which
we would be disposed to assign it, although it differs
somewhat from that, in its dermal skeleton. This, does not
present upon the abactinal surface, the peculiar
arrangement of calcareous plates, nor the multitude of
tentacular pores which are distributed on the entire abactinal
surface, both, upon the rays and the disk, right up to the
margin, and, further, it differs, in the concealed marginal
plates, and in their shape.
The body is strongly convex on the abactinal surface,
and flat on the actinal surface. It has 5 short thick rays
(Pl. XV, fig. 2). The disk-radius bears to the brachial
radius the proportion of, as 5:8.
The abactinal surface is clad with close-set, almost
chalice-formed paxillæ, having a narrow base, but broad
above. They are formed by a perforated calcareous
column, on whose superior free extremity, a number of
calcareous points project, which on the exterior margin, almost
assume a wreath form. Between the points, an extremely
thin, pellucid, membrane is visible, enveloping the whole
of the paxilla (Pl. XI, fig. 8). Between the paxillæ, very
numerous tentacular pores are distributed over the entire
abactinal surface, right up to the margin of the rays and
the interbrachial space.
The anal aperture is submesial. The madreporite, in
small specimens, is circular, but in the largest specimens,
it is a little oblong, and it is situated about midway
between the rays and the rounded margin of the starfish.
The ambulacral furrow is broad in the middle, and
narrow towards the extremities. It is furnished with two
series of spiculæ-free suckers provided with sucking disks
(Pl. X, fig. 1). Along the margin of .the furrow, there are
three series of spines, containing 2 spines in each series.
The 2 inmost spines are the longest (Pl. X, fig. 1,6) and
by meeting with the corresponding 2 spines from the
opposite margin, serve to cover the furrow.
The interbrachial spaces are triangular, and very
broad outwards, towards the margin (Pl. X, fig. 2). They
are closely beset with peculiar, elongate paxillæ, furnished
with 6—8 aculeæ. The entire paxilla is enveloped by
cuticle and epithelium, leaving, only, the aculeæ exposed (PI.
XI, fig. 7).
The marginal plates are almost concealed by the
thick integumental covering, and first, become distinctly
visible; either when the animal is dissected downwards from
the dorsal surface and the integument pushed back, and
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