som svarer til Synaptidernes saakaldte Kloak, Fig. 3, 2. 
Vi kunne vanskelig benævne denne Udvidning af Rectum 
Kloak, da vort Dyr ingen Tarmappendices (Lunger) har, 
ligesom der heller ikke aabne sig andre Organer i den ud- 
videde Rectum. Denne er i: hele sin Omkreds bundet til 
Kropsvæggen ved mange kortere og længere Muskeltraade, 
der tage deres Udspring fra Hudens Tvermuskler. 
Tarmens Vægge ere meget tyndere, end Mayens; men 
tykkest ere de dog i Endetarmen. Tarmen er efter hele 
sin Længde bundet til Rygfladen ved et Mesenterium, lige- 
som der hist og her udgaar fra Bugfladens Tværmuskler 
enkelte lange Muskeltraade, der fæste sig paa Tarmen. I 
histologisk Henseende er Tarm, Mave og Svælg bygget som 
hos Holothuriderne i Almindelighed. Tarmkanalen, især 
Rectum, var udfyldt af en lerholdig Masse. hvori fandtes 
forskjellige Foraminiferer. 
Kalkringen, det mdre Skelet, er her ligesom hos 
Slægten Hipidia dannet af 5 Stykker, og ikke som sædvan- 
ligt hos Holothuriderne af 10. Disse 5 Stykker, der svare 
til Radialstykkerne, have megen Lighed med dem hos Æl- 
pidia. Ethvert Kalkstykke er sammensat af et Midtparti, 
der er temmelig massivt og danner en afstumpet Kegle med 
en lidt flad For- og Bagside, Fig. 14, a. Fra Midtpartiets 
Forflade udspringe 4 krumme Stave, Fig: 14, b, der ere 
sammenvoxede paa Midten, saaledes nemlig, at 2de Stave 
danne en temmelig spids Bue, og alle 4 tilsammen et X 
med meget krumme Arme, der ere bredest ved Udspringet, 
ere runde og ende knopformigt. 
flader, noget bagtil, udsprmge ligeledes 4 gritfelformige 
Stave, 2 paa hver Side, hvoraf de to, der ere overordentlig 
lange, have en horizontal Retning, Fig. 14, c, imedens de 
to andre, der ere noget kortere, have en meget skjæv Stil- 
ling, Fig. 14, d. Disse 4 Stave, der i det Hele ere meget 
længere, end de forreste, ere ligeledes bredest ved Basis; 
deres Ender ere dels temmelig spidse, dels ere de kløftede. 
Det er de bagerste, lange horizontalt løbende Stave, der 
forene sig med de tilsvarende fra de tilgrændsende Kalk- 
stykker. som væsentlig danne den femkantede Ring. For- 
bindelsen sker ved Bindevæv: og paa den Maade, som Dr. 
Théel har paavist ved Elpidia. 
Fra Kalkringen udbreder sig en yderst tynd Binde- 
vævsmembran, som omgiver Spisergret og fester sig paa 
den bagerste Flade af Mundskiven, hvorved Svælgsinus 
dannes. Indenfor denne Membran sees en Mængde fine 
Bindevævstraade, der dels udgaa fra den ydre Flade af 
Svælget, dels fra Mundskiven, og som fæste sig paa Enderne 
af Kalkringens forreste Stave.. 
Den norske Nordhavsexpedition. 
Fra Midtpartiets Side- " 
Danielssen og Koren: Holothurider. 
in part acuminate and in part cleft. 
- 
middle of the cayity, horizontally backwards to the anus, 
fig. 8, h. This horizontal part, which must be regarded as 
a rectum, exhibits a rather conspicuous expansion, analogous 
to the cloacum in the Synaptidæ, fig. 3, 7. This, however, 
is hardly an appropriate term by which to designate the 
expanded rectum, the animal having no intestinal: appen- 
dages (respiratory tubes) or other organs opening into it. 
The rectum is webbed round the whole of its circumference 
to the wall of the body, by a number of muscular filaments 
of different lengths, issuing from the transverse muscles’ of 
the integument. 
The intestine has much thinner walls than the sto- 
mach; those of the rectum are however. thickest. The in- 
testine is connected by a mesentery throughout its entire 
length with the dorsal surface; here and there, too, divers 
long muscular filaments proceed from the transverse muscles 
of the ventral surface to the intestine. Histologically, the 
structure of the intestine, the stomach, and the gullet differs 
in no respect from that distinguishing those organs in other 
Holothurians. The intestinal canal — more especially the 
rectum — was distended with an argillaceous substance, in 
which were divers Foraminifera. 
As in the genus Hlpidia, the calcareous ring, or inner 
skeleton, is composed of 5 pieces, — not of 10, the dominant 
number in Holothurians. These 5 plates, corresponding to 
the radial lamme, present considerable resemblance to 
those in -Elpidia. Hach of these calcareous segments has a 
medial segment, rather massive, presenting the appearance 
of an obtuse cone, with the anterior and posterior surfaces 
slightly depressed, fig. 14, a. From the anterior surface 
of the medial segment protend 4 curyed rods, fig. 14, b, 
connate, in the middle, one with the other, each pair form- 
ing accordingly a rather pomted arch, and the 4 rods 
together an X-like figure, with round and exceedingly cur- 
vate arms, broadest at the point of origin, and terminating 
in a knob. From the lateral surfaces of the medial seg- 
ment, a little posteriorly, protend likewise 4 styloid rods, 
2 on either side; 2 of these rods, which are exceedingly 
long, extend horizontally, fig. 14, ¢; the position of the 
other two, which are somewhat shorter, being very oblique, 
fig. 14, d. These rods, too, which are much longer than 
the other 4, are thickest at the base; their extremities are 
It is the poste- 
horizontal rods, that unite with the corre- 
sponding rods from the adjacent calcareous segments, which 
principally constitute the pentagonal ring. The attach- 
ment is effected: by bands of connective tissue, and in 
the way pointed out by Dr. Théel in his description of 
Elpidia. | | 
From the calcareous ring extends an exceedingly thin 
membrane of connective tissue, enveloping the æsophagus, 
and connate with the posterior surface of the oral disk, 
whereby is formed the pharyngeal sinus. 
rior, long, 
Beneath this mem- 
brane are seen numbers of slender filaments of connective 
tissue, proceeding — part from the outer surface of the 
gullet, and part from the oral disk — to the extremities 
of the anterior rods of the calcareous ring. 
