Irpa’ abyssicola, n. g. n. sp. . 
P : 
Mala IW Tyee, il, 2 8 
Den Holothuride, ‘vi nu skulle beskrive, har, som vi 
senere skulle paavise, flere vigtige Bergringspunkter med 
Slegterne Elpidia og Kolga; men adskiller sig dog saa- 
meget fra dem, at vi have fundet det nødvendigt at danne 
en ny Slægt for den. Destoveerre maa vi beklage, at vi 
kun have havt et enkelt Exemplar til vore Undersøgelser, 
og selv dette var temmelig contraheret ved dets Opbevaring 
i Spiritus. Det blev optaget fra et meget stort Dyb (1050 
Favne), og under et overordentligt stormende Veir, saa det 
ikke var muligt at anstille videregaaende Iagttagelser, medens 
det levede. 
Legemet er 21”” langt, 6”” bredt, noget smalere 
imod den forreste tvert-afskaarne Ende, som er forsynet 
med 10 haandformig-fligede Tentakler, som sidde i en Krands 
rundt Kroppens forreste Rand, Tab. 4, Fig. 1, 2. Mund- 
skiven er lidt hvælvet og foldet, og Munden sidder næsten 
i Centrum, dog nærmere Bugfladen, Fig. 4%. Legemets 
bagerste Ende er afrundet, og paa dets Midte, nærmere 
Rygsiden er den lidt atlange Analaabning, Fig. 1, 2, a, a. 
Kroppen har en udpræget Bug- og Rygside. Bugsiden 
er lidt fladtrykt og glat, Fig. 1. Rygsiden er hvælvet, og 
har paa den øverste Trediedel 2 paalangsgaaende Rækker 
koniske Papiller, 4 i hver Række, iméllem hvilke sees to 
paatvers staaende større koniske Papiller. Rækkerne ere 
konvergerende forfra bagtil, og hver Rækkes Papiller staa 
lige overfor hverandre. De forreste Papiller ere fjernede 
omtrent 3”” fra Kroppens forreste Rand, Fig. 2. Strax 
bagenfor denne, imellem Grunden af 2 Tentakler, findes en 
lille rund Aabning for Kjønsorganernes Udførselsgang, Fig, 
2, b. Der, hvor Bug- og Rygsiden støde sammen, dannes 
paa hver Side og paa den bagerste Ende en afrundet Rand, 
og paa denne iagttages 24 eylindriske, stive Fødder, 9 paa 
hver Side, og 6 paa Enden, Fig. 1, 2. 
Dyrets Hud er læderagtig, seig og meget kontraktil: 
den dannes af en klar, yderst tynd, gjennemsigtig, struktur- 
løs Cuticula, indenfor hvilken er et enkelt Epithellag af 
Cylinderceller, der fester sig til Læderhuden (Corium). 
Denne er temmelig fast og bestaar af et stærkt fibrillært 
Bindevæv, i hvis ydre Lag forskjelligformede Kalklegemer 
ere leirede, Fig. 4, imedens i det indre findes spredte dels 
Celler med et kornet Indhold, lig Semper's Slimceller, dels 
forlængede Bindevævslegemer, og dels yderst smaa Kalk- 
korn. 
* Irpa er en Sagngudinde, tilhørende den nordiske Mythologi. 
Hun henregnedes til de onde Aander, som forlangte Menneskeofre 
for de Tjenester, hun ydede. 
Irpa* abyssicola, n. g. n. 
PL IDV, mem, Å, QB Å 
sp. 
The Holothurian we are about to describe, exhibits, 
as will afterwards be shown, several points of close resem- 
blance to the genera Hlpidia and Kolga, but is on the 
other hand so characteristically distinct from both, that we 
do not hesitate to establish a new genus for its recep- 
tion. We have, we regret to say, been unable to obtain 
more than a single specimen of this animal, and this indi- 
vidual had become a good déal shrunk from being pre- 
served in spirits. It was brought up from a very con- 
siderable depth (1050 fathoms), and in a heavy gale of 
wind, so there was no possibility of instituting comprehen- 
sive observations on the living animal. 
The body measures 21”” in length and 6”” in breadth, 
but is somewhat slenderer at the anterior truncated ex- 
tremity, which is furnished with 10 palmate-lobed tentacula, 
encircling the anterior margin of the body, Pl. 4, figs. 1, 2. 
The oral disk is slightly arcuate, the mouth itself being 
almost in the centre, a very little nearer the ventral sur- 
face, fig. 4". The posterior extremity of the body is 
rounded, and on the middle portion, slightly approx- 
imating to the dorsal surface, occurs the somewhat ovate 
anal aperture, fig. 1, 2, a, a. 
The body has a distinct dorsal and ventral surface. 
The ventral surface is slightly depressed and smooth, fig. 1. 
The dorsal surface is convex, and exhibits on its upper 
third two longitudinal series of conic papille, 4 in 
each series, between which are seen two larger, transversely 
placed conic papilke. The series are posteriorly convergent, 
and. the papille in each opposite one to the other. The 
foremost papillæ are removed about 3”” from the anterior 
margin of the body, fig. 2. Immediately posterior to the 
latter, between the bases of 2 tentacula, occurs a small 
circular opening, for the genital duct, fig. 2, b. Where 
the ventral and dorsal surfaces’ meet, extends on either 
side of the body, and round its posterior extremity, a con- 
tinuous convexed margin, disposed along which are seen 
24 cylindric, rigid suckers, 9 on each side, and 6 border- 
ing the extremity. 
The animal is covered with a tough, coriaceous, and 
in a high degree contractile integument, composed of an 
exceedingly thin, translucent, structureless cuticle, beneath 
which is a single epithelial layer of cylindric cells, webbed 
to the corium. The latter is firm in texture, consisting 
of strong fibrillous connective tissue, with multiform cal- 
careous corpuscles dispersed through its outer layer, fig. 
4; the inner exhibits a multitude of scattered cells, con- 
taining a granulated substance, like that in Semper’s mucous 
cells, and, exclusive these, elongate corpuscles of connec- 
tive tissue, and minute calcareous globules. 
* A goddess of Northern Mythology. She was classed among 
the evil spirits, being a malignant deity, to whom were offered human 
sacrifices as the price of her favour. 
