Omkring Munden har den en brunrød Ring. Dyret kryber 
paa Tentaklerne. 
Hudens histologiske Bygning afviger ikke væsentlig 
fra Holothuridernes i Almindelighed. Den dannes af en 
fuldkommen gjennemsigtig og strukturløs Cuticula, Fig. 2, a, 
under hvilken et Lag Cylinderepithel, Fig. 2, b, der støder 
umiddelbart til et tykt, hyalint Bindevævslag, Fig. 2, ¢, 
hvortil Muskelhuden (Tvær- og Længdemuskler) er fæstet. 
Hele Kroppens indre Flade er beklædt med et flimrende 
Peritoneum. 
Det hyaline Bindevæv er overordentlig rigt paa for- 
skjelligtformede Legemer, der ere snart ovale med en eller 
to: Udløbere, Fig. 2, d, snart ere de mere eller mindre for- 
grenede, saaledes at de lange fine Udløbere korrespondere 
med Grene fra andre lignende Geller, hvorved et fint Net- 
-værk oftere fremkommer, Fig. 2, e. Disse samtlige Celler 
have en Kjærne, der ikke er meget stor, og som er omgiven 
af et tyndt Lag Protoplasma. | 
En saadan Rigdom af forgrenede Bindevævslegemer 
have vi ikke tidligere stødt paa; vi vare 1 Begyndelsen til- 
bøielige til at antage dem for Nerveceller; men nærmere 
Undersøgelser bragte os fra denne Antagelse; thi de havde 
ikke Nervecellens egentlige Karakter; Kjernen 
for liden og Protoplasmaindholdet for fattigt, og det var os 
ikke muligt at sætte dem 1 nogensomhelst Forbindelse med 
de Nervetraade, vi fandt i Huden. Dr. Théel har i sine 
var meget 
Bemærkninger til Myriotrochus fundet lignende Legemer i 
Huden, som han antager for Nerveceller, men vi ere ikke 
langtfra at tro, at denne Antagelse hviler paa en Misfor- 
staaelse. ' 
I Bindevævslaget, indenfor Epithelet, men beklædtYaf 
dette, findes de tidligere omtalte Hjul fleirede, Fig. 2, f. 
Med Hensyn til disse have vi kun lidet at foie til Steen- 
strup's Beskrivelse. Den Flade, der vender udad, er skaal- 
formig fordybet, og Centrumet, hvorfra Radierne udgaa, 
danner en liden, rund, knopformig Fremstaaenhed, der er 
forsynet med smaa Pigge, Fig.2. g. Det er til denne Del, 
at det Bindevævsbaand er fæstet, som danner Stilken. 
Radierne variere i Antal; det samme er Tilfældet med de 
paa Hjulperipherien anbragte Tapper, Fig. 2, h, eller Tæn- 
der, der altid ere tilstede i større Mængde, hvilket gjør, 
at de snart sidde imellem to Radier, snart lige paa dem. 
« Den bredere Del af Tappen er paa sin”ydre Flade forsynet 
med et afrundet' Indsnit, Fig. 2, 7, hvilket bidrager til at 
give Hjulets Peripheri en undulerende Form, saaledes som 
af Dr. Théel antydet. : 
Foruden Bindeveevslegemerne findes hist og her i 
Corium et intens brunrgdt Pigment, dels i Klumper, dels 
indesluttet i særegne Celler. Ringmusklerne ere ikke af- 
brudte af Længdemusklerne eller Nervestammerne, men gaa 
rundt Legemet og dække Radialnerverne, der altsaa ligge 
imellem dem og Huden. 
Paa Kroppens indre Flade, op imod Kalkringen, findes 
en Mængde yderst smaa, fritstaaende Legemer, der have en 
noget. forskjellig Form, men hvoraf Bladformen er den 
30 
Round the mouth it has a brown-red ring. The organs of 
motion are the tentacles, on which the animal creeps. 
The histological structure of the skin does not differ 
essentially’ from that in other Holothurians. Underneath 
the cuticle, which is translucent and structureless, fig. 2, a, 
extends a layer of cylindric cellular epithelium, fig. 2, b, 
connate with a thick hyaline layer of connective tissue, 
fig. 2, c, webbed to the muscular integument (consisting of 
transverse and longitudinal muscles). The entire inner sur- 
face of the body is clothed with ciliated peritoneum. 
The hyaline connective tissue has dispersed through- 
out it numbers. of corpuscles, varying in form, some oyal,. 
with one or two prolations, fig. 2, d, some more or less 
branched, the long, slender ramifications corresponding with 
those from other similar cells, and thus frequently constitut- 
ing an intricate network, fig. 2, e. The cells have all of . 
them a nucleus, not very large, which is invested with a 
thin layer of protoplasma. 
Such an abundance of ramifying corpuscles we have 
never before met with in the connective tissue; indeed, we 
were at first disposed to regard them as nervous cells; but 
on further examination, the falsity of this assumptive view 
soon became apparent; for these corpuscles have none of the 
characters peculiar to a nervous cell; the nucleus is much 
too small, the protoplasmatic contents are too meagre, and we 
failed to discover any connexion whatever with the nervous 
filaments observed in the skin. True, Dr. Théel, as ap- 
pears from his notes on Myriotrochus, has observed similar 
corpuscles in the integument, which he takes to be nervous 
cells; but we are almost afraid he has been misled in 
putting forward such an assumption. 
In the layer of connective tissue, underneath the epi- 
thelium, are imbedded the rotated calcareous corpuscles 
mentioned above, fig. 2, f, with regard to which we have 
but little to add to Professor Steenstrup’s description. The 
exterior surface is calyx-shaped, and the central point from 
which the radii proceed constitutes a small, round, tuber- 
cular apophysis, furnished with minute spinules, fig. 2, g. 
It is to this part that the membranous ligament forming 
the stem is attached. The radii vary m number; the same, 
too. is the case with the cogs or teeth; fig. 2, h, on the 
periphery of the rotated corpuscles, which, being very 
numerous, occur sometimes between the radii, sometimes on. 
them, The broad part of the cog, or tooth, has on its 
outer surface a rounded incision, fig. 2,7, which, as noticed 
by Dr. Théel, helps to give an undulary form to the peri- 
phery of the rotated corpuscle. 
Exclusive of the corpuscles of connective tissue, occurs 
every here and there im the corium a deep brownish-red pig- 
mentary substance, either in isolated lumps or deposited in 
peculiar cells. The annular muscles are not decussated by 
the longitudinal muscles or the nervous trunks, but encircle: 
the body, covering the radial nerves, which extend accord- 
ingly between ‘the annular muscles and the skin. 
On the inner surface of the body, in elose proximity 
to the calcareous ring, are seen numbers of exceedingly 
minute isolated corpuscles, varying somewhat in form, which, 
