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16
Randpigge, samt imellem disse og de dorsale Randpigge, er
tæt besat med ligeformede Pedicellarier, Fig. 2, b.
Langs Ambulacralfuren, ved Grunden af Papillerne,
sees enkeltstaaende, meget store, langstilkede, ligeformede
Pedicellarier, der rage ind i Furen.
Hvad nu Pedicellarierne betræffer, saavel de lige som
korsdannede, saa skulle vi til Sammenligning levere et Par
Tegninger af dem, men forresten henvise til Ed. Perrier’s
Beskrivelse af dem; kun er at bemærke, at den
pyramide-formige Forlængelse af Basaldelen hos de ligedannede
Pedicellarier ikke ender i - en Spids, saaledes som Perrier har
fundet det paa de Exemplarer, han har undersøgt, men at
Enden er afrundet og forsynet med en dyb Fure, Fig. 6, a.
Hudskelettet paa Ryggen af Armene er sammensat af
meget smaa, lidt aflange, smale Kalkstykker, der taglagt
lægge sig paa hverandre og danne derved spinkle Bjelker,
som 4netformigt forene sig saaledes, at meget store Masker
fremkomme, hvori sees Grupper af Kalkkorn, imellem hvilke
findes Tentakelporerne, Fig. 7, a, b.
Paa Skivens Ryg ere Kalkstykkerne større, Maskerne
noget tættere, Tentakelporerne færre, og i dens Centrum
antage Kalkbjelkerne en vis Regelmæssighed, idet de
udgaa fra et Centrum henimod Peripherien, Fig. 7, c.
Paa Armenes Sider, just der, hvor udvendig den
beskrevne Række Pigge, som begrændser Rygfladen, findes,
sees en Række smaa, flade, noget forskjelligt formede
Plader, der snart ere aflange, snart 3-kantede og snart
nærmende sig Korsformen; mén alle bære de en Pig, der, som
tidligere omtalt, er omgiven af en Krands korsdannede
Pedicellarier. Disse Plader kunne betragtes som dorsale
Randplader, Fig. 7, d.
Bugens Hudskelet bestaar af en Række langt fra
hverandre staaende, næsten korsformede, større Kalkplader, Fig.
7, e. 8, som paa Enden af Korsets ydre Arm, Fig. 8, a,
bære en lang, stærk Pig, halvt omsluttet af Pedicellarier,
der tidligere ere beskrevne. Korsets indre Arm, Fig. 8, b,
lægger sig umiddelbart til 2—3 Adambulacralplader, idet
der imellem disse og hin er placeret en lille, lidt aflang,
tynd, konkav-konvex Kalkplade, Fig. 9, der ved stærke
Ligamenter er bunden til begge. Paa den indre Flade (den,
der vender til Kropshulheden) af disse korsformede Plader,
henimod det egentlige Skelet, sees dels et enkelt, lille
Kalk-stykke, dels flere smaa, næsten runde Kalkklumper, Fig. 7, g,
der støde i Regelen til to Adambulacralplader, saa at disse
heller ikke her staa i umiddelbar Forbindelse med de
nævnte korsdannede Kalkplader, som kunne betragtes som
ventrale Randplader. Disse forenes stundom med de
dorsale Randplader ved et lille, smalt Kalkstykke, stundom
ventro-marginal spines, and also, between these and the
dor-so-marginal spines is closely beset with rectiform
pedicellariæ (fig. 2, ft).
Along the ambulacral furrow, at the base of the
papillæ, occasional, very large, solitary, long pedunculated,
rectiform pedicellariæ, protruding into the furrow, are to be
seen.
In regard to the pedicellariæ forcepif ormes, both
rectiform and cruciform, we present a couple of
illustrations to facilitate a comparison; but, we would refer to
Ed. Perrier’s description of them, remarking only, that the
pyramidal continuation of the basal portion in the
rectiform pedicellariæ, does not terminate in a point, as
Perrier has observed in the specimens he has examined, but
that the extremity is rounded, and furnished with a deep
furrow (fig. 6, a).
The abactinal dermal skeleton of the rays is constructed,
of very small, somewhat elongate, narrow calcareous
ossicles, laid imbricate upon each other, and form, thus,
slender rods which unite in such a reticulation, that very
large meshes are produced; in these meshes, groups of
calcareous corpuscles are seen, between which, tentacular
pores are found (fig. 7, a, b).
On the disk’s abactinal surface the calcareous ossicles
are larger; the meshes closer; the tentacular pores less
numerous; and, in the mesial portion, the calcareous rods
assume a certain regularity of disposition, in as much, that
they here proceed from a common centre towards the]
periphery, fig. 7, c.
On the lateral surfaces of the rays, just outside where
the spinous series bordering the abactinal surface’is found,
there appears, a series of small, flat, dissimilar formed
plates, occurring, sometimes oblong, sometimes tri-lateral, and
occasionally, approaching to the cruci-form, but all of them
carrying one spine, which as previously stated is environed
by a wreath of cruciform pedicellariæ forcepiformes. —
These plates maybe considered to be dorso-marginal plates
(fig. 7, d).
The ventro dermal skeleton is composed, of series
of considerably interspaced, largish, nearly cruciform,
calcareous plates (figs. 7 e, 8), which carry on the exterior
brachial [extremity of the cross, a long strong spine, (fig. 8, a)
which is semi-enclosed by the pedicellariæ previously
described. The inner arm of the cross, does not quite
closely abut, with 2—3 adambulacral plates; there being
situated between these and the. former, a small, somewhat
oblong, thin, concavo-convex calcareous plate fig. 9 which
is connected to both, by strong ligaments. On the interior
surface of these nearly cruciform plates, (that facing
towards the body cavity) towards the skeleton-proper, there
appears, occasionally, a single small calcareous ossicle,
occasionally, several, small, almost round, calcareous
corpuscles (fig. 7, g) which, as a rule, abut with 2
adambulacral plates, in such manner, that neither do they in this
situation, stand in immediate union with the cruciform cal-
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