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32
Paa Expeditionen blev der kun fundet det ene
Exemplar, som vi har havt til vor Undersøgelse. Paa dette
Exemplar var Huden brusten, og endel af Tarmkanalen
udfalden; men da Dyret var temmelig stort og godt
conserveret, kunde Iagttagelserne dog anstilles med temmelig
Nøiagtighed. Hvad vi nedenfor levere, er følgelig kun
nogle Tillæg og Bemærkninger til Dr. Théels Afhandling
over hans Myriotrochus Rinkii; thi det har destoværre ikke
været os muligt at erholde Huxley’s Arbeide over Chirodota
brevis.
Legemet er cylindrisk, noget smalere i den bagerste
Ende, 60"" langt, 15"*" bredt paa det Tykkeste. Huden,
der er glat, gjennemsigtig, saa de indre Dele sees, er
fornemmelig paa Rygsiden besat med smaa Hjul, der som
hvide, glindsende Punkter sees med blotte Øine. 12
finger-formig forgrenede Tentakler, der vel kan trækkes ind i
deres egen Stilk, men ikke ind i Kroppen,- saa at de ganske
skjules.
Huden bestaar af en glasklar, strukturløs Overhud
(Cutieula), der dækker Epithellaget, som dannes af
Cylinderceller. Indenfor dette er et temmelig bredt Lag hyalint
Bindevæv, hvori findes en stor Mængde forgrenede
Binde-væv8legemer, indeholdende en større eller mindre Kjerne,
omgivet af Protoplasma, fuldkommen lig dem, som vi have
omtalt hos Myr. Rinkii. Fig. 5, a. Udløberne
korrespondere hyppig med hverandre, saa derved fremkommer et
udbredt Netværk med store Masker. Denne Anordning af
Bindevævslegemerne har ikke saa ganske lidet tilfælles med
det saakaldte Slimvæv hos høiere Dyr.
Det hyaline Bindevæv gaar over i et tydeligt udpræget
fibrillært, hvori Fibrene ligge lagvis. Fig. 5. b, b, med
mellemliggende Lag hyalint Bindevæv, Fig. 5, c, c. Det
er væsentlig i dette de ovenomtalte forgrenede
Bindevævsceller findes; men de saaes ogsaa — dog meget sparsomt
— i de fibrillære Lag. Disse danne tilsammen et næsten
dobbelt saa bredt Belte, som det hyaline Bindevævslag.
Det fibrillære Bindevæv støder umiddelbart til
Ringmusklerne, der ikke afbrydes af Længdemusklerne eller
Radial-nervefne, men gaa rundt hele Kroppen.
De 5 Længdemuskler, der fortil fæste sig paa den
udvendige hule Flade af Radialstykkernes Processer, og
bagtil omkring Analaabningen, ere enkle og bundne til
Ringmusklerne ved Bindevæv. Hele Muskellaget er beklædt
af Peritoneum med et flimrende^ Epithelovertræk. Fra
dette, især fortil ved Kalkringen, findes de af Théel
omtalte Legemer, der rage frit ind i Kropshulheden. Foruden
de af ham afbildede to Former tindes der ogsaa flere
andre, der nærme sig noget de af os nævnte hos Myr.
On the Expedition, one individual only was met with,
which we have had submitted to us for examination. The
skin of this specimen was cracked in places, and pai*t of
the intestinal canal had dropped out; the animal being
however rather a fine specimen, and in a good state of
preservation. comparatively accurate observations could
notwithstanding be instituted. A few additional data,
supplementary of Dr. ThéePs Memoir on his Myriotrochus Rinkii,
is therefore all we purpose furnishing here; for Professor
Huxley’s treatise on Chirodota brevis was unfortunately not
to be had in any of our libraries.
The body is cylindric. a trifle slenderer at the
posterior extremity, and measures 60"™ in length.’ its greatest
thickness being 15""". The skin, which is smooth, and so
transparent that the inner organs can be distinctly seen
through it, exhibits. • more especially on the dorsal surface,
numerous small rotated corpuscles, visible to the naked eye
as white, lustrous points. The animal is furnished with 12
digitated tentacula, which admit of being retracted within
their own stem, but not into the body, so as wholly to
conceal them.
The skin consists of a crystalline, structureless
cuticle. covering the epithelial layer, which is composed of
cylindric cells. Underneath the latter extends a rather
broad layer of hyaline connective tissue, throughout which
are dispersed large numbers of ramose corpuscles of
connective tissue, each with a nucleus, varying in magnitude,
surrounded by protoplasma, exactly similar to those we noticed
in our description of Myr. Rinkii, fig. 5. a.« The ramifications
frequently correspond, each with each, thus forming an
extensive large-meshed network. This arrangement of the
corpuscles of connective tissue has not a little in common
with the mucous tissue, as it is called, in animals of
higher organization.
The hyaline connective tissue coalesces with another,
exceedingly fibrillous, the fibrils being disposed in layers,
fig. 5, b, b, with interjacent layers of hyaline
connective tissue, fig. 5, c.j c. It is chiefly the latter in which
occur the ramose cells of connective tissue described above;
but they were also observed — though in very limited numbers
— in the fibrillous layers. These constitute together a
membranous belt, nearly twice as broad as the hyaline
layer of connective tissue. The fibrillous tissue is
contiguous with the annular muscles, which are not intersected
by the longitudinal muscles or by the radial nerves, but
go right round the body.
The 5 longitudinal muscles, which, anteriorly, are
attached to the outer hollowed surface of the processes
issuing from the radial plates, and. posteriorly, to the
margin of the anal opening, are simple, and webbed to the
annular muscles by connective tissue. Over the whole of
the muscular layer extends the peritoneum, invested with
a ciliated epithelial tunic. Here, anteriorly in particular,
near the calcareous ring, begin to occur the corpuscles
noticed by Dr. Théel, which project freely into the peri-
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