held 
der fæster sig paa Basis af hver Analtand. Disse Længde- 
muskler ere fæstede dels til selve Corium, dels til Tver- 
musklerne ved en Mængde Bindevævstraade. hvoraf der 
udgaar mindst en fra hver Tvermuskel. Saavel Længde- 
som Tyermusklerne ere beklædte af et Peritoneum, der er: 
yderst tyndt og gjennemsigtigt, og dannes af en hyalin 
Grundmasse, hvori findes en Mængde Bindevævsfibre, spredte 
Muskelfibre' og runde Kalklegemer, Tab. WIDE 1888, 183 
dets frie Flade har et flimrende Epithelovertrek. 
Hvor Huden paa Mundskiven danner de tidligere om- 
talte rørformige Forlængelser, er den meget tynd, halv 
gjennemsigtig, og i den egentlige Hud findes Bindevævs- 
fibre og yderst sparsomt runde Kalklegemer, fuldkommen 
lig dem, som findes i Peritoneum; dette overtrækker Røre- 
nes indre Flade, saa at ogsaa her iagttages det samme 
Epithel, som i Kropshulheden. | 
De Kalklegemer, som giver Huden sin Fasthed og 
Støtte, findes som sædvanligt i det ydre Lag af Corium, 
Tab. VIII, Fig. 19, e. De have en forskjellig Form, efter- 
som de indtage Legemets Midte, eller dets Ender, og frem- 
stille sig egentlig under 2 Hovedformer, nemlig de smaa, 
dels elliptiske, dels runde Legemer, og de store, mere sam- 
mensatte Legemer, hvis Grundform er trearmet. - 
De elliptiske Legemer have en smuk vinrød Farve, 
ere fra, 0.045—0.089”” lange, fra 0.086—0.071”” brede; 
de bestaa af en næsten rund, temmelig mørkerød: Kjerne, 
en lysere rød peripherisk Del, og have megen Lighed med 
en virkelig Celle med dennes Kjerne og Kjernelegeme, Tab. 
VIII, Fig. 16, ay a. Ved meget stærk Forstørrelse viser 
det sig, at de ere dannede af concentriske Lag. 
: De runde Kalklegemer ere enten farveløse, eller de 
have en yderst svag, dels brunlig. dels violet Farve. De 
have en Størrelse fra 0.026—0.088””. bestaa af flere og 
færre Facetter og have et straalet Udseende, saa at man 
teller fra 3—10 Straaler, alt efter Facetternes Antal, Tab. 
VIT, fig. 16, 6, b. Af disse Kalklegemer, saavel de ellip- 
tiske, som runde, findes der en stor Mængde; de ligge 
stundom tæt ved Siden af hverandre, stundom ligge de 
mere spredte imellem de store Kalkplader, som nu skulle 
beskrives, aldrig ligge de pakkede op paa hverandre. 
De store Kalklegemer have en forskjellig Form, alt 
eftersom de findes paa Midten af Legemet, eller i dettes 
begge Ender; men alle have den trearmede Grundtype, 
Tab. VIII, Fig. 30—34. De Kalklegemer, der findes paa 
den største Del af Legemet, bestaa, naar de ere fuldt ud- 
viklede, af en gjennembrudt Plade, Fig. 27, dl, og af et 
fra denne udgaaende Skaft eller Krone, Fig. 30. Pladen 
dannes af et Centrum, hvorfra udgaar 3 Arme; hver Arm 
deler sig et kortere eller længere Stykke fra Centrum i 2, 
Fig. 25, a, hvoraf hver Gren, idet den voxer, bøier sig 
indad og støder til en tilsvarende Gren fra en anden Arm, 
hvorved fremkommer et’ Hul, Fig. 24. Enhver Plade be- 
paratively thin tendon, which is attached to the base of 
each anal denticle. These longitudinal muscles are webbed 
partly to the corium and partly to the transverse muscles by a 
number of filaments of connective tissue, one, at least, pro- 
ceeding from each transverse muscle. The longitudinal and 
the transverse muscles are both invested with a peritoneal 
membrane, exceedingly thin and translucent, which consists 
chiefly of a hyaline substance, strengthened by a number 
of fibres of connective tissue, isolated muscular fibres, and 
round calcareous corpuscles, Pl. VIII, fig. 18; its free 
surface has a covering of ciliated epithelium, 
The integument on the oral disk, where it forms the 
tubular prolations described aboye, is exceedingly thin and 
semi-translucent; and in the corium are seen fibres of con- 
nective tissue and a very limited number of round calcareous 
corpuscles, perfectly similar to those in the peritoneum; 
the latter extends over the inner surface of the tubes. and 
here too, accordingly, is observed the same “epithelium AS 
in the perivisceral cavity. 
The calcareous spicules that serve to give strength 
and firmness to the integument are, as is commonly the 
case, dispersed ne the outer layer of the corium, 
Jelly VILDL ng, 318), They vary in form and size, accord- 
ing as they occur in the middle of the body or at the ex- 
tremities; the small spicules are some elliptic and some 
round; the large ones, more complex in structure, are: 
mostly trifid. 
The elliptic spicules, of a beautiful vinous red, are 
from 0.045”" to 0.089” Jong and from 0.036" to 0.071” 
broad; they consist of an almost circular, dark-red nucleus, 
a light-red peripheral portion, and bear considerable resem- 
blance to a true cell, with its nucleus and nucleolus, Pl. 
VII, fig. 16, a, a. When highly magnified, they are seen - 
to be built up of concentric layers. 
The round spicules are either colourless or have a 
faint tinge, some of brown and some of violet. | They mea- 
sure in diameter from 0.026” to 0.088””, have a greater 
or less number of facets, and present a radiate appearance, 
the number of rays, from 3 to 10, varying with’ that of 
the facets, Pl. VIII, fig. 16, 0, b. These calcareous spi- 
cules, both the elliptic and the eireular, are exceedingly 
‘humerous; in some places they lie close together, in others, 
between the large calcareous laminæ, which we shall next 
describe, they are more dispersed; they never lie packed 
one above the other. 
The large spicules vary in form, according as they 
occur in the middle or at the extremities of the body; they 
are all of them however of the fundamental trifid type, 
PL VIII, fig. 80—34. On the greater part of the body 
the calcareous spicules, when fully developed, consist of 
a perforated lamina, fig. 27, 31, and of a shaft or corolla, 
fig. 30, The lamina has a centre-piece. from which pro- 
ceed 3 arms; each arm divides “dichotomously at some 
distance from the centre, fig. 25, a, and each offshoot, du- 
ring the progress of its growth, bends gradually over to meet 
a corresponding offshoot from another arm, thus forming 
an orifice, fig. 24. Hach lamina has therefore 3 elliptic- 
