kun hos ældre Individer ligge de tættere sammen’ og danne 
næsten et sammenhængende Lag, hvorved de nærme sig 
meget baade i Form og Anordning de, der findes hos Troch. 
boreale, Fig. 19. Saavel de runde Kalklegemer som de ellip- 
tiske bestaa af koncentriske Ringe og have en skjøn, mørk- 
vinrød Farve, kun enkeltvis ere de gule, Fig. 241. De 
ovale have i Midten ligesom en Kjerne, der altid viser sig 
med en intensere Faryve. 
Den anden Form at Kalklegemerne ere farvefrie, 
gjennembrudte Plader, fra hvis Midte 
armet Krone, der har en knopformig fri Ende, forsynet 
med 3 eller 4 runde Takker, Fig. 24, 'f. Det er denne 
Ende og endel af Skaftet, som rager op igjennem de om- 
talte Papillers Aabning. Saavel Pladen som Skaftet er 
beklædt af et tyndt Lag af Bindevev, der danner ligesom 
en Skede om Skaftet, hvilken er dækket af Epithelet ‘og 
Cuticula, ' Fig. 24, g. Disse Kalklegemer findes 1 stor 
Mængde overalt paa Kroppen, men ere dog saavidt spredte, 
'at de ikke ligge tæt i hverandre, uden paa begge Krops- 
enderne, Fig. 20. Her have de en mere langstrakt Form, 
Fig. 19, og ligge saa tæt til hverandre, at de f. Ex. paa 
den forlængede Haledel danne saagodtsom et Pantser. Og- 
saa disse Legemer have særdeles meget tilfælles med de 
Kalkplader, der findes hos Troch. Thomsonii: og boreale. 
reiser sig en tre- 
Den tredie Form af Kalklegemer er ganske eien- 
dommelig og minder om Tilværelsen af en Synapta, der 
forlængst er forsvunden. Det er disse Legemer, der danne 
den tidligere omtalte Stjerne, og som udgjør et Komplex 
af 5—6 spatelformige Kalkstave, Fig. 24, h, et Kalk- 
anker, Fig. 21. Dette stjerneformige Legeme er inde- 
sluttet af en Hulhed, der dannes af Bindevævet, og 
‘ydre Flade er beklædt af Epithelet, Fig. 24, 7, 7. Saavel 
Bindevævet som Epithelet forlenger sig’ et Stykke op paa 
Ankerstokken, men Klgerne ere nggne. ” 
og 
. 
Enhver spateldannet Kalkstav bestaar af et meget 
langt og rundt Skaft, der som oftest er afrundet paa den 
fri Ende, Fig. 21, a, og en bredere Del, eller Blad, der 
er næsten rundt, temmelig tykt og forsynet med en stor 
Mængde Huller, Fig. 21, b. Det er disse bredere Dele 
med’ deres afrundede Rande, der støde til hverandre og 
danne Stjernens Centrum, imedens Skafterne danne Straa- 
lerne, Fig. 20, 21. Til Midten af Stjernens Centrum er 
fæstet ved Bindevæv et bevægeligt Kalkanker, Fig. 20, 21. 
Ankerstokken er rund, meget lang, og den Del, der er 
fæstet til Spatelbladene, har 5—6 listeformige Fremstaaen- 
heder, alt eftersom Stjernen dannes af 5 eller-6 Stave, Fig. 
_ 21, c. Ankerets Kløer ere lange og tilspidsede, og pat 
deres ydre konvexe Rand ere tre Takker, Fig. 21, d. 
Ankeret kan bevæge sig til alle Sider ved sin ligamentøse 
Sammenheftning, 
hvis 
68 
type, which are the most numerous, . 
‘ 
generally occur em- 
bedded in groups, fig.’ 24, e; in mature individuals only do 
they exhibit a closer arrangement, constituting an almost 
continuous layer, and hence approximating in form and 
disposition those in Troch. boreale, fig. 19. Both the round 
and the elliptic corpuscles consist of concentric rings, and 
are of a vivid vinous red, a few only being yellow, fig. 241. 
The oval corpuscles have in the centre a kind of nucleus, 
invariably of a deeper colour. 
The corpuscles exhibiting the second form are colour- 
less perforate plates, from the centre of which springs a 
three-armed corolla, having at its free extremity a knob, 
furnished with 3 or 4 cylindric spines, fig. 24, f. It is 
this extremity, together with part of the shaft, that pro- 
tends through the opening in the papillæ mentioned 
above. Both the plate and the shaft are invested with a 
thin layer of connective. tissue, the shaft being, as it were, 
invaginated in a sheath, covered by the epithelium and the 
cuticle, fig. 24. g. These calcareous corpuscles occur every- 
where in large numbers on the body, but their arrangement, 
saving at the extremities. is not so close as to bring them in 
direct contact one with the other, fig. 20. Here (at both 
extremities) they are more elongate in form, and so closely 
disposed, that in places, on the caudiform appendage for 
instance, they constitute a kind of.armature. These cor- + 
puscles, too, have much in common with the calcareous 
plates in Troch. Thomsonii and Troch. boreale. 
The third typical form in which these calcareous cor- 
puscles occur is eminently characteristic, indicating, it would 
seem, a Synapta stage of development, out of which the ani- 
It is these corpuscles that 
they constitute, 
mal has long since passed. 
form the stellate figure mentioned above, 
too, a complex of spatulate calcareous rods, 5 or 6 in number, 
fig. 24, h, as also. a calcareous anchor, fig. 21. This stel- 
late figurefoccurs in a depression, or cavity, in the connec- 
tive tissue, and has its outer surface clothed with the epi- 
thelium, fig. 24, 7, 7. The connective tissue and the 
epithelium are both prolonged some distance up on the 
stock of the anchor; but the arms are naked. 
G The spatulate rods consist. each of an exceedingly 
long, eylindrie shaft, rounded, as a rule, at the free extre- 
mity, fig. 21, a, and of a ront pinnate portion, almost 
round, rather thick, and. furnished with numerous apertures, 
fig. 21, b. It is these broader parts with their rounded 
margins that approximate to form the centre of the stellate 
figure, the shafts representing the radii, figs. 20; 21. Web- 
bed to the centre of the stellate figure, is seen a moveable 
calcareous anchor, figs. 20; 21. The stock of the anchor 
is cylindric, exceedingly long, and the part webbed to the 
spatulate lobes is furnished with linear apophyses, 5 or 
6 in number, according as the stellate figure consists of 5 
ot of 6 calcareous rods, fig. 21, c. The arms of the anchor 
are long and pointed, and their outer convex margin has 
3 spines, fig. 21, d. The anchor is moveable in all direc- 
tions, by means of its ligamentous connexion ‘with the stel- 
late figure. 
