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31
hyppigste. De have en Længde fra 0.015—0.030"", ere
fæstede til Peritoneum ved en Stilk, der udvider sig noget
ved Tilheftnings8tedet. Den frie Ende er som oftest
bredere, og synes at have en elliptisk Aabning, Fig. 3. Disse
Legemer have et kornet’ Indhold og svare til de, der ere
beskrevne af Grube, Sars, Semper, Théel og Flere, hos
Synaptiderne. Vi have kun undersøgt disse Legemer paa
Spiritusexemplarer.
Stenkanalen, der er yderst kort, omtr. 0.8"", bestaar
af en noget krumbøiet Sæk, der er udfyldt med et
sammenhængende Kalknæt, der strækker sig noget ud paa
Vand-karringen, just paa det Sted, hvor Stenkanalen udmunder,
Fig. 4. — Endelig skulle vi bemærke, at paa
Radialnerverne, lige ved deres Udspring fra Nerveringen, findes en
Blære paa hver Side af Nervestammen ; men disse Blærer
indeholde ikke Otolither, og bestaa af en fast gjennemsigtig
Membran, beklædt paa sin indre Flade med Epithel, aldeles
tilsvarende det hos Dr. Théels Art.
Ifølge de Undersøgelser, vi have anstillet, staar det
for os klart, at den Art. Théel har iagttaget og tildels
beskrevet, ingenlunde er Myriotrochus Rinkii, men efter al
Sandsynlighed er den samme som Huxley har beskrevet
under Navnet Chirodota brevis; idetmindste antager Théel,
at hans og Huxley’s Art ere identiske, ligesom han
formener, at dersom det konstateres, at den grønlandske Art
stadig har stilkede Hjul, maa hans og Huxley’s danne en
fra Rinkii forskjellig Art.
Vore Exemplarer, hvoraf vi have en stor Mængde,
ere fra Spitsbergen; de have alle stilkede Hjul, og svare
forresten ganske til Steenstrup’s og Liitken’s Beskrivelser,
ligesom vi ogsaa have havt et Originalexemplar tål vor
Disposition. gaa vi kunne ikke være i Tvivl om, at det er den
virkelige Rinkii, • vi have undersøgt. Sammenholde vi nu
vore Iagttagelser med de af Théel anstillede, saa fremgaar
deraf, at Théels Art frembyder saamange Afvigelser fra
Myriotrochus Rinkii, at den nødvendigvis maa danne en fra
denne forskjellig Art.
Myriotrochus (Chirodota) brevis, Huxley.
1852. Chirodota brecii, Huxley. Journal of a voyage in Baffin’s Bay
and Barrow-Strait in the year 1850—51 by P. C. Sutherland;
Vol. 11, Appendice, pages 221 et 222.
1865. Oligotrochus eitr nu, M. Sars. Om arktiske Dyreformer i
Christianiafjorden. Videnskabs-Selskabets Forhandlinger for 1865,
Pag. 200. Fuldstændigere beskrevet og afbildet i Fauna
littoralis Norvegia*, 3die Hefte, Pag. 4».
1*77. Myriotroehus Rinkii, Théel. Note sur quelques Holothuries des
Mers de la Nouvelle Zemble. Upsala, 1877.
however, in the great majority is petaloid. They measure
in length from 0.015""’to 0.030"", are affixed to the
peritoneum by a stem, which slightly expands at the point of
attachment. The free extremity is as a rule broadest, and
furnished apparently with an elliptic opening, fig. 3. These
corpuscles contain a granulary substance, and are the
analogue of those met with in the Synaptidoe, described by
Grube, Sars, Semper, Théel, and others. Save in
spirit-specimens, we have not examined these corpuscles.
The sand-canal, which is exceedingly short, about
0.8"" in length, has the form of a slightly arcuate sac,
filled with a network of calcareous reticulations extending
out on the water-vascular ring, to the exact point at which the
canal disembogues, fig. 4. — In conclusion, we must not
omit to observe, that the radial nerves, at their origin on
the nervous ring, are furnished with a vesicle on either
side of the nervous trunk; but these vesicles do not
contain Otoliths; they consist of a close-textured transparent
membrane, clothed on its inner surface with an epithelial
layer, exactly as in Dr. Théel’s species.
As the result of our investigation, we feel convinced,
that the species observed and briefly described by Dr.
Théel, cannot be Myriotrochus Rinkii, but is most probably
identical with Huxley’s Chirodota brevis; indeed, their
specific identity is assumed by Dr. Théel himself, who opines
that, in the event of the Greenland species invariably
having the rotated corpuscles pedunculate, his and Huxley’s
must be regarded as specifically distinct from Myr. Rinkii.
Our specimens — we have a large number — are
from Spitsbergen; they have all of them the rotated
corpuscles pedunculate, and in other respects agree closely
with Steenstrup’s and Ltitken’s descriptions; moreover, we
have had before us an original specimen, and hence there
can assuredly be no doubt whatever that the subject of
our examination was the true Rinkii. On comparing
our observations with those of Dr. Théel, his species is
found to differ in so many respects from Myriotrochus Rinkii,
that it cannot but be regarded as specifically distinct.
Myriotrochus (Chirodota) brevis, Huxley.
1852. Chirodota breeis, Huxley. Journal of a voyage in Baffin’s Bay
and Barrow-Strait in the year 1850—51, by P. C. Sutherland;
Vol. 11, Appendix, pages 221 and 222.
1865. Oligotrochu* ritreut, M. Sars. Om arktiske Dyreformer i
Christianiafjorden. Videnskabs-Selskabets Forhandlinger for 186.’»,
Pag. 200. Described more at length, and figured, in Fauna
littoralis Norvegia?, Part 3, p. 49.
1877. Myriotrochui Rinkii, Théel. Note sur quelques Holothuries des
mers de la Nouvelle Zemble. Upsala, is77.
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