Mao, Wy Ile, 
Tab. VI, Fig. 
«1 
 ydre Ende til Huden: 
81, 
10. 
TAR 
12. 
«ere leirede, 
13. 
14. 
15. 
16. 
-Encellede Slimkjertler ; 
Vingeformige Radier ; 
Kalkringen med Vandkarsystemet, og et 
Hudparti, forstørret. a Kalkring; 0, b 
de to Processer paa de to dorsale Radial- 
stykker; c den Poliske Blære; d Vand- 
karringen; e Længdemuskel. ; 
Stenkanalen af samme - Dyr, forstørret. 
a Ligamentet, der fester Stenkanalens 
b Madreporpladen 
med sin ujevne, takkede Overflade; c den 
egentlige Kanal; d, den bredere Del, 
hvorved den: udmunder i Vandkarringen. 
Tversnit af Huden af den bagerste Ende 
at Acanthotrochus mirabilis, forstørret. a 
Cuticula med det derunder liggende Ep:- 
thellag; 6 Hyalint Bindevæv; c, ¢ Binde- 
vævslegemer; d Bindevævslegemer med 
kornet Indhold (Sempers Slimceller); e, e 
f Ringmuskler; I 
Længdemuskel; g Nervekarret sammen- 
voxet til Nervens indre Flade; h Nerve- 
karret, der er aabent til Nervens ydre 
Flade; 7 Nervestammens lysere, bredere 
Lag: k Nervestammens mørkere Parti, 
der er sammenyoxet med Karret. 
Acanthotrochus mirabilis 1 omtrent natur- 
lig Størrelse. 
Den samme forstørret, 1 hvis gjennemsig- 
tige Hud Kalkhjulene sees. ligesom Tarm- 
kanalen viser sig tydeligt. 
Stilkløse Legemer, der rage frit i Krops- 
a, å Spredte Epithelceller. 1 
Peritonealovertrækket, forstørrede. 
Lignende Legemer, men stilkede og blad- 
formige, forstørrede. 
Et Stykke Hud, hvori de forskjellige Hjul 
forstørret. a, a De store 
Hjuls Tænder. 
Det store Hjul, stærkere forstørret. a, ‘a 
b trekantet Rum 
ce. Tand paa Hjulets 
hulheden: 
imellem to Radier 
ydre Rand. 
Det mindre Hjul; 
Vingeformige Radier: 
to Radier; 
indre Rand. 
Kalkringen, forstørret. a 
Længdefure; b, b de to Processer paa to 
Radialstykker; c en Proces paa hvert af 
de øvrige tre Radialstykker; d Interradial- 
stykket paa Ryggens Midte; e Halvmaane- 
formigt Indsnit. 
Et Stykke af Kalkringen, seet fra Siden, 
lidt stærkere forstørret. a Radialstykkets 
Legeme; b dets Proces; c Længdefure; 
b Mellemrummet 
for ce Tender paa Hjulets 
seet fraoven, 
stærkt forstørret. a - | 
Pl. V, fig. 
Pl. VI, 
fig. 
or 
10. 
gly 
12. 
13. 
14. 
15. 
Caleareous ring, ‘aquiferous system, and 
part of the skin, magnified: å calcareous 
ring; b, b: the two processes on the two 
dorsal radial segments; c vesicle of Poli; 
d water-vascular ring; e longitudinal muscle. 
Sand-canal in same animal, magnified: a- 
the ligament by which the outer extremity 
of the sand-canal is attached to the skin; 
b madreporie body with its rough indented 
surface; ¢ sand-canal;, d the broad part 
through which it opens HED the water- 
vascular ring. 
Transverse section of the skin a the pos- 
terior extremity of Acanthotrochus mirabilis, 
magnified: -@ cuticle with underlying epi- 
thelial layer; b hyaline connective tissue ; 
CC corpuscles of connective tissue; d cor- 
puscles of connective tissue with granulous 
contents (Semper's mucous cells); e, & uni- 
cellular mucous glands: f” annular Muscles; 
I longitudinal muscle; 
connate with inner 
g nervous vessel 
surface of | 
nervous ‘vessel open towards outer surface 
of nerve; 7 the broad, light-coloured layer 
of the nervous stem; k the darker section 
of the nervous stem, connate with the vessel. 
Acanthotrochus mirabilis, about the natural 
size. 
Same animal magnified, showing the calcare- 
ous wheels through the translucent skin: 
the intestinal canal, too, 
ceptible. E 
Non-pedicellate corpuscles projecting freely 
into the perivisceral cavity: a, a isolated — 
epithelial cells in the peritoneal tunic. 
Similar corpuscles, but pedicellate and leaf _ 
shaped; magnified. 
nerve; h 
is distinctly per- 
A piece of the skin in which the calcare- 
ous wheels are embedded, magnified: a, a 
teeth of the large wheels. 
One of the large wheels more highly mag- 
nified: a, å wing-shaped radii; 0 triangular 
space between two of the radii; c teeth on 
outer margin of wheel. 
One of the small wheels highly magnified: 
a wing-shaped radii; b space between two 
of the’ radii; 
wheel. 
c teeth on inner margin of 
The calcareous ring, viewed from above, 
magnified: a longitudinal furrow; b, b the 
two processes on the two radial segments; 
c process on each of the three remaining 
radial segments; d the interradial segment 
on the middle of the back; e lunate incision. 
Segment of the calcareous ring, lateral 
aspect; more highly magnified: a corpus” 
of radial segment; b its process; c longi- 
